I'd rent a game with souljaboy, just to see him get killed over and over. The guy basicly had one hit, which was popular for dubbed "Barney the Dinosaur" episodes.
A game with 'Lil Wayne? Sure. Laughing my ass off trying to understand what he's actually saying, while he's getting killed. Go for it!
The only good rappers would be a group. Like The Game, not because they're great (since every rapper basically is a phony), but because that would probably allow for a great 4-player co-op game.