There are two major, major attributes about Vice City that make it a nearly perfect game: the extremely non-linear ways in which missions can be finished, and the plot/characters. For example, in one mission, you have to rescue Lance from the bad guys in a junkyard. My brother rammed a car into the cars blocking the entrance but bailed out right before it hit. It destroyed both cars and killed the guards there. Then he ran inside with the AK-47 I believe (the first person rifle) and took everyone else out. It took a few tries (ok, 10) but it did work.
My friend did this mission the same way, except he blew up the cars in the front first with grenades, then drove inside and killed everyone with a gun.
I went and got the garbage truck and drove it through the cars in the beginning, killing both guards. I parked the garbage truck beside Lance, rescued him, and both of us drove out of the junkyard with dozens of guys shooting at us. By the time I made it to the hospital to fix up Lance, three tires were blown out on the garbage truck and a literal dozen of enemy vehicles were chasing me.
You can finish any mission in nearly anyway you want to, and that's what makes the GTA series so fucking awesome. On top of that, the voice acting is most excellent (better than a lot of movies) and the plots are always top-notch. Nothing beats Tommy's drug-runner in the factory after getting beat up by Sonny's men. Tommy finding out about it. The drug operator says, "Tommy, rip him a new asshole for me!" Tommy Vercetti turns around with a handgun, and storms off screaming "I'M GONNA RIP HIM TWO!" I think he might be the biggest videogame badass ever.
My favorite mission? Hell, I liked all of them. My favorite weapon? Umm, whatever I had at the time.
My favorite car is easily the Comet, though. That, or maybe the Blista Compact (CR-X, ha ha). Both of those cars handle like a dream. I remember that by the time I was at the end of the game, I could finish the hardest race mission that gave $100,000 without hitting a single lightpost or car in the game. That race has you go around the entire city in one lap as well, all against other racers. I always did it with the Comet or Blista Compact.
Rockstar knows what the hell they're doing. I would honestly love to have another game with Tommy Vercetti. He's one of my favorite videogame characters ever. If Rockstar simply changes the plot for the next GTA game and leaves EVERYTHING else the same, I guarantee it will be a hit just as 3 and Vice City were.
-Lasereth