I don't know what slobby's on, but I want some. Actually, no I don't.
GTA IV is a living, breathing world. The graphics are amazing, the characters are well fleshed out and believable, and there's a lot to do besides the main mission (which is engrossing). You'll mean to put it on for half an hour and three hours will just fly by.
Seriously, I can't recommend it highly enough.