This is actually more fun than the original GTA IV and TLaD, although they were pretty good too.
I like how the brighter, more Vice City-like atmosphere of this game contrasts with GTA IV and the other episode TLaD. If you're a fan of GTA, get this.
Make sure you press pause when your mother walks in the room, though. The sheer number of unneccessary F words, and if I'm not mistaken, a couple of C words, mean that this game could easily outswear the South Park movie! The game also contains strong violence and some scenes of sex, but if you're familiar with GTA then you'll know what to expect.