Could anyone tell me what game this was?

A couple of years ago, before I had either the XBox360 or the PS3, I had the misfortune of playing a really good racing game on one of these consoles in a store. It was an off-road racing game with really good graphics, and intense tracks where you were sometimes jumping from one cliff to another. The vehicles I was driving were 4x4 off-roaders, but not ATVs (although I think that may have been an option). It also had nitro boosts. Any help would be greatly appreciated as I really liked the game.