Why do you watch a particular team? What draws you to the game? Everybody has their own answers to these questions. For some of us, it’s a question of family and loyalty. Perhaps someone in your family cheered for a particular team and it just caught on with you. Maybe you went against the current, and purposely supported the rivals of teams your friends and family supported and it just stuck. There’s also the issue of supporting a particular player. Individual athletes can become something of idols or rockstars whom we follow and support over their careers. Of course, in most cases, you support the team your favorite personality plays for and even continue this support long after the athlete has moved on or retired.

Whatever the reason and whoever you support, sports fans know that not all games are created equal and some are more important than others. Yes, playoff games, cup competitions, and matches that will get you into the playoffs are all important. However, within this realm there is one type of match which can trump all other – the match or game against a rival. The rival is your most hated enemy. No matter how well or poorly your team or your team’s rival are doing, when they come together the resulting game takes on massive importance. Fans circle the days on calendars and television companies drool in anticipation of the viewership bump when two arch-rivals lock horns.

The following looks at 25 of the biggest sporting rivalries in the world. These rivalries are based on a number of factors. Religion, geography, class, history, politics – all might sound like the offerings at some local school, but every rivalry has its basis in one or more of these. Some of these sporting rivalries are more violent than others, while some are watched by more people. Some are far older, while others have seen the rivalry fade a bit, only to intensify decades later. You may not be familiar with them all, but rest assured, even if you’re not a fan of any of the teams, clubs and organizations listed here, you likely know the emotion and intensity involved in any sort of sports rivalry.

25 25. Boston Bruins vs Montreal Canadiens

An ‘original six’ rivalry, there remains little love lost between these two sides, even today. Combining both regular season and the playoffs, no two NHL teams have played each other more than these two. With 34 playoff series meetings and nine Game-seven deciders, it’s no wonder these two teams have developed such a strong rivalry. In terms of silverware, it’s not even close. The Canadiens dominate the Stanley Cup department with a record 24 versus the Bruins’ 6. From the 1920s to the mid-80s, you’d be a fool to bet against the Canadiens whenever they met the Bruins in a series. This dominance dropped off a bit over the past 30 years with the crew from Bean Town taking a small advantage in playoff series wins. Nonetheless, with all the history between these two great sides, any future meeting is bound to create a story.

24 24. S.L. Benfica vs F.C. Porto

O Classico is the term applied to any domestic match that takes place between Portuguese football rivals Benfica and Porto. This rivalry dates back to 1912 and has seen 230 matches played between the sides with Porto coming out on top with 89 wins. Initially, Benfica dominated the matchups and enjoyed a period of significant success in the 1950s and 1960s. Porto responded with a string of successes in the 1990s and a Champions League title in 2004. The two have never met in European competition but each club has two European Cup-Champion’s League trophies meaning domestic success carries even more weight in deciding arguments among rival fans.

23 23. New York Yankees vs New York Mets

This rivalry seems pretty obvious considering they are two teams in the same city. That said, there is no real competition between these two sides when it comes to who has been the better one. The Yankees have 27 World Series titles and 40 pennants. The Mets have 2 World Series titles and 4 pennants. Nevertheless, a rivalry exists and each side’s fans boo each other whenever they meet. The ‘subway series’ has seen the two teams face off a total of 103 times. That’s not a lot considering how many times teams usually play each other. Of course, the fact that the Yankees are an AL team and the Mets are a NL team restricted the chances to play one another until interleague play was adopted in the late 1990s. The Yankees lead the series with 56 wins and also boast the biggest victory of 15-0 in June, 2009.

22 22. SS Lazio vs AS Roma

If you’re looking for large crowds, fan violence, and a generous amount of racist and fascist banners, look no further than the rivalry between Roman footballing clubs Lazio and Roma. The Derby della Capitale is definitely one of the fiercest in the world. This rivalry has its origins in the 1920s, with Benito Mussolini and his desire to create a super-club from several smaller city teams capable of competing with Italy’s best teams. Lazio held out from the merger and the rest is history. With over 170 matches played between the two sides, Roma hold the advantage in this rivalry with 64 wins, 62 draws and 48 losses.

21 21. San Francisco Giants vs Los Angeles Dodgers

A long time ago (not in a galaxy far, far away), the Los Angeles Dodgers and San Francisco Giants were both based in New York. In the late 1950s, both teams moved across the country to California. What had been a city rivalry developed into a cross-state rivalry as each team established its new home. The rivalry started in 1890 and continues today, witnessing over 2400 games. Overall, the Giants have a slight lead in wins with 1210 versus the Dodgers’ 1184. Further bragging rights are handed to Giants fans given their team has won 8 World Series and 23 pennants versus the Dodgers’ six and 21. That this rivalry has endured a cross country move and relocation in two separate cities, makes this all the more remarkable.

20 20. Michigan vs Ohio State

This college football rivalry goes all the way back to 1897 when the Wolverines of the University of Michigan crushed the Ohio State University Buckeyes 34-0. Ohio State achieved their first win over Michigan 22 years later. Up until the 1950s, Michigan had a record of 30-12-4 against the Buckeyes. Since the 50’s, Michigan has generally kept a 12 game win gap between them and their rivals and currently sit at 58-46-6. Each side has made 43 Bowl appearances with Michigan holding the edge in National and Big Ten titles while Ohio State has more Heisman Trophy winners and Big Ten Division titles.

19 19. Arsenal vs Tottenham

The rivalry between Arsenal and Tottenham Hotspur truly started in 1913 when the Gunners moved locations from Plumstead to Highbury in North London. Tottenham supporters saw Arsenal moving in on their turf and the rivalry only intensified over the coming decades. It’s a rivalry which has been largely one sided with Arsenal taking most of the wins and having more success in the league and cup competitions than their North London neighbors. Since 1992, Arsenal have more derby wins and more league titles and have only finished below Spurs in the table twice. Nonetheless, both sides take each derby very seriously and each match has the atmosphere of a cup final.

18 18. State of Origin: New South Wales vs Queensland

There’s a good chance many North American readers haven’t heard of this Australian rivalry, yet it is one of the biggest and most explosive in the rugby world. The State of Origin series pits clubs from New South Wales and Queensland against each other in a yearly three-match series which officially began in 1982. Interstate matches were not a new thing in Australian rugby, but the State of Origin series stipulated that you could only be recruited for a particular state’s team if you had played your first senior rugby league match there. It may not have the fanfare of an international tournament, yet the State of Origin series certainly has the feel of one. Rough play and fighting are a part of the series and it’s not uncommon to hear the commentator exclaim that there’s “nothing wrong with that,” when two players start throwing punches.

17 17. Dallas Cowboys vs Washington Redskins

The team of America’s capital versus America’s team. This rivalry began even before the Dallas Cowboys franchise existed. Clint Murchison Jr. was a Texas oil tycoon who wanted his own NFL team in the 1950s. Murchison tried buying the Washington Redskins from George Preston Marshall but the deal fell through. He then pushed for the creation of an expansion team which was blocked by Marshall until the Redskins owner found out Murchison owned the rights to Washington’s fight song. A deal was reached and the Cowboys were born. In the expansion draft, the Cowboys picked the Redskins’ star quarterback who was left unprotected. This rivalry has deep roots and, after 100 head-to-head games, favors the Cowboys who are 64-44-2.

16 16. Duke vs North Carolina

In college basketball, there are few rivalries bigger than that between the Blue Devils and the Tar Heels. Since 1920, these teams have battled it out and both have played a significant role in determining the ACC champion over the past several decades. In part, what makes the rivalry intense is the fact that the two schools are quite different. Duke is a private school, while UNC is a public university. At just 10 miles apart, the close proximity helps keep the rivalry extra strong. To date, UNC maintains bragging rights with a head-to-head record of 133-105. In addition, the Tar Heels have one more (5) NCAA Tournament Championship and have the sole post-season victory when these two teams met in 1971.

15 15. Inter vs Milan

Since 1908, this footballing rivalry has been one of the biggest not only in Italy, but the world. The Derby della Madonnina sees Milanese rivals Inter and AC Milan battle it out at least twice a year. What makes this derby and rivalry even more intense is that each team calls the same stadium home (San Siro), making matches even more intense. In top-flight Italian football, Inter have maintained a slight edge over their inter-city rivals. That said, Milan hold the edge in cup and European competitions. In terms of silverware, these teams’ respective success means Inter have a slight lead in domestic silverware (30-29), while Milan have a bigger haul of total trophies to brag about (47-39).

14 14. Chicago Bears vs Green Bay Packers

The Bears and Packers first battled it out in 1921 and have had 190 meetings. The rivalry started from day one when a Bear (who were then known as the Staleys) threw a punch and broke the nose of a Packer. It’s been love ever since. There’s not a lot to divide these teams and the Bears hold a slight lead in the series at 93-91-6. These divisional rivals have 22 NFL Championships between them and have supplied the Hall of fame with a small army of players.

13 13. Fenerbahce S.K. vs Galatasaray S.K.

In the case of this rivalry, it really is a city divided. Both clubs are located in the Turkish city of Istanbul which is divided by the Bosphorus. Fenerbahce are on the Asian side of Istanbul while Galatasaray are located on the European side. The two clubs first played each other in 1909, but it wasn’t until 1934, following a game which saw significant fouling and on-field violence, that the rivalry really started. Since then, violence and vandalism have become a common occurrence whenever these clubs meet. In terms of records, each has claimed 19 league titles. Galatasaray have a Europa league title and take an advantage in domestic cups with 28 versus Fenerbahce’s 15.

12 12. Boston Celtics vs L.A. Lakers

Magic Johnson versus Larry Bird. There’s more to this rivalry than just two great players, but to many, that sums up a lot. The Celtics and Lakers are the most successful teams in NBA history with 17 and 16 Championships, respectively. That’s almost half of all the NBA Championships ever won. In the NBA’s early days, the Lakers were dominant and only the Celtics proved a real threat. In fact, in their first head-to-head Finals meeting in 1959, the Celtics swept their opponents, handing the Lakers their first ever Finals loss and paving the way for a Celtic dynasty. The two teams have played 354 times with Boston edging out the race with 197 victories versus the Lakers’ 157.

11 11. Celtic vs Rangers

From Boston to Glasgow we find a different team named Celtic. The city rivalry of Celtic and Rangers is well known in the footballing world. While many derbies were ruled by politics and history, this one was dominated by politics, religion and class - the Protestant-Conservative Rangers battling the Catholic-Labour Celtic. Fan violence became the norm whenever these two met and a pitch invasion in 1980, complete with brawling supporters, led to the banning of alcohol on Scottish grounds. The Old Firm derby may not be as intense or fueled by religion and class as it was a few decades ago, but it continues to be one of the biggest rivalries in world football.

10 10. Baltimore Ravens vs Pittsburgh Steelers

If you want to see an example of two teams and two sets of fans who do not like each other in the NFL, look no further than the Baltimore Ravens and Pittsburgh Steelers. These AFC North members are known for playing a no-holds barred game whenever they face each other. Rough hits, controversial calls, and threatening statements all make this rivalry one bordering on pure hate. In 41 all-time meetings, the Steelers maintain the edge of a 24-17 record. Steelers fans will also brag that they need two hands to display all their Super Bowl rings, with six versus the Ravens’ two.

9 9. Boca Juniors vs River Plate

The Superclasico is one of the ultimate footballing rivalries in the world. According to one journalist, this Buenos Aires derby is said to make the Old Firm match look like a child’s game. The teams represent very different classes in the city. Boca Juniors are associated with the working class, while their rivals are associated with the more affluent. The fierce rivalry on the pitch has often spilled over into the stands. In 1968, this reached deadly levels when Boca Junior fans panicked and ran for the exits only to create a crush. Seventy-one fans were killed in an event which further emphasized the severity of this footballing rivalry. In total, Boca lead the series with 127 wins since 1905.

8 8. Montreal Canadiens vs Toronto Maple Leafs

Two ‘Original Six’ teams, the rivalry between the Canadiens and Leafs was initially fuelled as much by English versus French as by the fact they were teams from Canada’s two largest cities. Even children’s literature felt the wrath of this rivalry – as seen in The Hockey Sweater. These teams have met 790 times with Montreal leading the series 383-313-88. Leafs fans get their own chance to laugh when you consider Stanley Cup final head-to-heads in which the Leafs have won four of six encounters. The introduction of the Ottawa Senators somewhat reduced the rivalry, although the move of the Leafs to the Northeast Division in 1998 brought the two old rivals together again.

7 7. India vs Pakistan

Cricket can be a hotly contested sport and has seen many fierce rivalries develop between nations. In the case of India and Pakistan, this cricket rivalry stands apart as it has been fuelled by politics and war. The religious division of India in 1947 and subsequent fighting over Kashmir has long stoked the fires of this sports rivalry. Wars and terrorist acts have caused matches to be cancelled on several occasions, and these meetings have often seen a strange mix of tensions and diplomacy. Nevertheless, it’s taken very seriously – so seriously there is even a case of students being expelled from an Indian university for cheering for Pakistan. Each side has its own bragging rights with India leading in World Cup and T20 wins and Pakistan leading in Test and ODI victories.

6 6. Liverpool vs Manchester United

Take two teams from England’s industrial North-West, make them two of England’s most successful footballing sides and what do you get? Probably one of the biggest rivalries in English football. Liverpool and Manchester United are two of England’s biggest clubs and have dominated for stretches over the past 40 years. With the appointment of Sir Alex Ferguson, Manchester United made it a mission to knock Liverpool off their “perch,” and domestically they did just that over the course of the Premier League era. The Red Devils have enjoyed more league and domestic cup wins, while Liverpool have maintained bragging rights over European success with five Champions League trophies. The dislike these two clubs have for each other even goes down to the players who have been involved in numerous on-field incidents over the years.