Remember when Pete Carroll and USC ruled the college football world? The Trojans' fall began in 2009 and it can all be traced back to what Jim Harbaugh's Stanford team did to them at the Coliseum that season. After the Cardinal thumped USC 55-21, Carroll wasn't thrilled with Harbaugh running up the score, and the two got in a verbal argument at midfield at the end of the game. Both coaches have since moved on to the NFL and will do battle Sunday for the right to play in the Super Bowl. If it turns into a one-sided affair, don't be surprised if Harbaugh or Carroll doesn't hesitate to run it up.
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Nick Saban vs. Les Miles
Miles took over as LSU head coach when Saban left for the Miami Dolphins after the 2004 season. When the Tigers won a national title three years later, many critics said Miles did it with "Saban's players." Things heated up when Saban returned to the college game at Alabama. LSU won the 2011 regular season meeting in Tuscaloosa, but the Crimson Tide shut out the Tigers in the rematch at the BCS championship game two months later. Both teams are annual top contenders in the SEC, but Saban holds a 5-3 record vs. Miles and has won the last three meetings.
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LeBron James vs. Kevin Durant
It's not Kobe vs. LeBron anymore. Durant and LeBron met in the NBA Finals in 2012 in what many expect to be just the first of many championship round clashes. Both players are in their prime and their teams have been the favorites of its respective conferences the past few seasons. LeBron silenced the critics by winning back-to-back titles, while Durant is still in the hunt for his first. There's no hate in this rivalry as the two NBA superstars are good friends off the court.
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Manny Pacquiao vs. Floyd Mayweather
No punches have ever been thrown in the ring between these two, but the fight to make it happen is still ongoing. Let's hope the wait isn't too much longer. Father Time may come into play as the years pass. Mayweather is still undefeated with 45 wins at age 36. Pacquiao, 35, bounced back in November from back-to-back losses and claimed the WBO International Welterweight title. There was hope for Mayweather vs. Pacquiao when talks began in 2009, but negotiations continue to fall through.
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Ronda Rousey vs. Miesha Tate
What started off as a competitive rivalry between two of the top women MMA fighters in the world has blossomed into a full-fledged hate between them, complete with Twitter-wars, reality shows, armbars, boyfriend insults and snubbed handshakes...and their fans are loving every minute of it. After Rousey defeated Tate back in 2012, the UFC paired them up as coaches on "The Ultimate Fighter," where tension was at an all-time high for the duration of the reality show. At the conclusion of the show, Rousey defended her UFC Bantamweight title against Tate at UFC 168, a show that drew the promotion's second largest gate in company history. Despite losing a second time to her, Tate has recently said she'd fight Rousey over-and-over again, and you can bet we'll all be ready to watch.
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Alexander Ovechkin vs. Sidney Crosby
Like Mario Lemieux and Wayne Gretzky, Alexander Ovechkin and Sidney Crosby will always be linked together. Ovechkin was selected first in 2004 by the Washington Capitals, Crosby went No. 1 in 2005 to the Pittsburgh Penguins...and the two have been trying to out-perform each other since. Both have won Hart Trophies (league MVP), both have lead the league in scoring, yet only Crosby has won a Stanley Cup. And now, thanks to realignment, the Penguins and Capitals now play in the same division in the Eastern Conference, helping to intensify their rivalry. The two will next compete against each other at the Winter Olympics in Sochi where Crosby will lead Team Canada against Ovechkin's Team Russia...both favored to bring home the gold medal.
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Tiger Woods vs. Phil Mickelson
When Woods came onto the scene in 1996, golf would never be the same. Mickelson had been a pro since 1992, but Woods took the world by storm quickly as the youngest player to ever in a major championship in 1997. Mickelson didn't get his first major title until 2004. Four years earlier, he snapped Woods' six consecutive tournament win streak in the 2000 Buick Invitational. The two continue to be the face of the sport even as a new generation of golfers being to move into the spotlight.
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Lionel Messi vs. Cristiano Ronaldo
The two greatest players on the two greatest teams in Spain (and possibly, the world). You can take all of the great sports arguments of all-time about who was better between two legends in their prime...and they might not stack up to what we are witnessing right now between Messi and Ronaldo. Websites are devoted, tracking every stat between the Barcelona and Real Madrid stars. The last six "Player of the Year Awards" (FIFA POTY and the Ballon d'Or) have been won between the two. And with both teams still in Champions League contention as well as both sitting atop the La Liga standings, this season will only add to what has become one of the greatest rivalries in sports history.
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Rafael Nadal vs. Roger Federer
There are some storied rivalries in the history of tennis, but this one will go down as arguably the best. Nadal and Federer have dominated the sport for the past decade taking turns at the top of the ATP rankings eight of the last 10 years. Since their first meeting in 2004, Nadal holds a 22-10 advantage. And in what many considered the greatest match of all time, Nadal defeated Federer in the 2008 Wimbledon final. Nadal has had the upper hand as of late -- winning all four meetings with Federer in 2013.
These two future Hall of Fame quarterbacks have been going at it for more than a decade, but it never gets old. Brady and Manning will meet for the 15th time, and fourth time in the playoffs this weekend. Brady holds a 10-4 advantage but this will be the first playoff game he will face Manning in Denver. The last time they met in the postseason was the 2006 AFC Championship Game when Manning went on to win his only Super Bowl with the Indianapolis Colts. Brady already has three, but lost his last two Super Bowl appearances against the other Manning.