I've played a few of them but not excessively because I find in the end I just get bored. However, one exception: GTA San Andreas? I got hooked in a big way. The fact that they had everything in it from the start says enough, really. No need for DLC when the initial game is good enough on it's own, and that means less money spending just to get to the stage that you can call it a great game.

All this and I barely even scratched half of the game's map, I suppose that just shows how immense that game was. I just... loved it.