Saints Row is a total Fred Durst wanna-be wigger fantasy GTA game but it's a damn good one. It's the only GTA clone that's ever beat GTA at its own game, at least as gameplay is concerned and if GTA 4 doesn't copy a some of the mechanics from Saints Row then I'll be one fucking sad panda.
GTA kicks the living shit out of Saints Row in the humor/atmosphere department though. The radio stations/commercials/storyline/pedestrians....all awful. I remember reading on GAF about how SR was supposedly a satire of gang culture, but it didn't come across that way at all to me. It seemed retardedly serious and all attempts at humor (Freckle Bitches...ugh) fell completely flat.
Still, it's a really fun game to play.