World Series Champs
2013 Red Sox
2007 Red Sox
2005 White Sox
2004 Red Sox
All of these teams had made important free agent signings, but these were not generally teams that had made monster free agent signings. The 2013 ALCS is a good example of this: the Red Sox had dumped off a ton of dead weight on the Dodgers in August of 2012 and used that money to sign lower-profile free agents like Mike Napoli and Shane Victorino.
On the other hand, the Tigers had made a huge bet by signing Prince Fielder to a huge contract before the 2012 season and it didn't work out. They probably could have signed three or four quality players with the money they committed to Prince and would have been a more complete team.
Who were the monster free agents on those teams? Outside of the 2009 Yankees, I only see 2.
-Barry Zito (7 years/$126 million), who was left off the roster for the Giants in 2010, and was solid in 2012. Overall, he was a total bust and one of the worst free agent signings ever.
-Manny Ramirez ($8 years/160 million): He was signed to a huge contract before the 2001 season and was a very important contributor to the 2004 and 2007 Red Sox teams.
- C.C. Sabbathia: 7 years/$161 million
- Mark Teixeira: 8 years/180 million
- AJ Burnett: 5 years/82 million
The Yankees are a special case, but it only worked once for them in recent years. It is a big difference, of course, if the team handing out the monster contract has a virtually unlimited budget, but it can still be a big mistake depending on who they are giving the money to. The Cardinals showed how to let an aging star walk away and end up as a stronger team in the long run.
There is a pretty clear lesson for teams other than the Yankees (although it probably applies to them to) about handing out monster free agent contracts. The teams that have won the World Series over the past 10 years have done it (or in spite of) without monster free agents.