Naruto: Ultimate Ninja Storm's 3.9GB doozy. According to Gamers Platform, who are currently playing a retail build of the game, the install takes about 15-20 minutes. You might want to clear up some space if you're planning to pick up the game on November 4 when it finally hits stores.
If you've got limited space on your hard drive, then you must be looking out for other titles with mandatory installs. Here's a brief list of other popular fall titles which have the space-eating "feature": LittleBigPlanet (500MB), Spider-Man: Web of Shadows (1GB) and Fallout 3 (4.3GB).