I gave up SA because of a mission where you had to shoot a load of geezers on a train whilst you were on a dirtbike. So, I didn't even leave LA to explore the massive game map.
GTA IV was good, until I got utterly bored by trying to keep up with friends. By that stage, I thought I'd sort my life out, switch off the console and keep up with friends. I think, had SA not had that irritating mission, I would have said it was the best. But, Vice City for me.