Games like GTA IV for Xbox 360?

[Vanilla]

Quite big I would say (Saints Row 2). Not as large as San Andreas, but if i remember correctly, it should be a just a tad larger than GTA IV. At least large enough that the planes and helicopters makes sense. There is a lot of funny mini-games inside the game, such as insurance fraud where you have to jump in front of cars and get hit, as well as base jumping. You can also pimp your car to a much larger degree than you could in GTA SA.