The fans' top 5 who couldn't walk away
1. Muhammad Ali
Ali lost his heavyweight title to Leon Spinks in 1978, but was able to get it back in a rematch seven months later. Following the win, Ali retired. But the retirement was short-lived as he returned to face Larry Holmes to try to win an unprecedented fourth title. His trainer refused to let him come back out after the 11th round, marking his first defeat by anything other than decision. He also lost to Trevor Berbick in 1981 before retiring again, this time for good.
2. Brett Favre
Brett Favre used to be known as one of the greatest QBs of all time. But now it seems like he's more well known for being the quarterback who just can't stay away. He retired for the first time after the 2007 season. Favre changed his mind, though, and after an ugly breakup with the Packers he was a Jet. After fading down the stretch, he retired again after the season, but here we are on the cusp of the 2009 season and he's starting for the Vikings.
3. Michael Jordan
Michael Jordan won 6 NBA Championships and 5 MVPs. He took a one-year absence from the NBA to try his hand at baseball, but he came back to lead the Bulls to a second three-peat before retiring again in 1998. But Air Jordan couldn't stay away and came back in 2001 with the Wizards. This comeback didn't go as smoothly as he had lost much of his explosiveness. He still averaged more than 20 ppg in both seasons, but it clearly wasn't the same M.J.
4. Larry Holmes
Larry Holmes won his first 48 bouts, beating, among others, Muhammad Ali and Ken Norton. Holmes successfully defended his title 20 times, second only to Joe Louis. He retired after two losses to Michael Spinx but made a series of comebacks. He was able to get three more title shots (1988, 1992 and 1995) but was unsuccessful in each. He finally retired for good after defeating Butterbean in 2002 at the age of 52 with a record of 69-6.
5. Willie Mays
Willie Mays is widely considered one of the greatest baseball players of all time. He finished his career with a .302 batting average, 660 home runs and 1,903 RBI. As great as his final numbers were, though, Mays really tailed off at the end of his career. Seeing Mays had lost a step, the Giants traded the beloved Mays to the Mets. He lasted two seasons with New York and finished his final season with a .211 average, six homers and 25 RBI.