Got a case of the Mondays? Well I've got the cure, right here: Death Rally [Free]. We gave the game five stars in our review, and I'd go as far as to say that Death Rally is easily among the best top-down racers available on the App Store if not the best. Seriously, don't miss it. I'll do some more convincing after you watch the trailer:

Death Rally has tons of things to unlock, tons of Game Center achievements to earn, and a constant stream of updates has kept this game remarkably fresh. There's even talks of a multiplayer mode on the way, so if nothing else, snag Death Rally to be ready for that.