SPOILER ALERT! SPOILER ALERT! SPOILER ALERT! SPOILER ALERT!
If you haven't beaten Vice City, please do not read this post.
1) DIRECT DEPOSIT. You shouldn't have to go collect your money from your assets. They should direct deposit into your account.
2) NO BOSSES. People like Lance Vance Dance and Sonny Forrelli took too long to kill. They're human just like everyone else in the game that is not you. They should go down w/ one shotgun hit.
3) MORE EFFICIENT WEAPONS. The range of sniper rifles should be extended. Also, smg's like uzi's and mp5's shouldn't take a million shots to kill one person. They are still bullets afterall, rapid fire or no rapid fire.
4) MORE EFFICIENT BREAKS. The breaks should be available to make turning easier while speeding, not just to slow the car down to a stop.
5) PEDESTRIAN ENHANCEMENTS. In Vice City, you start off as an ex con just out of prison. Pedestrians, should treat you like any average Joe Shmoe. But when you take over an entire city, they should move out of your way when you're walking down the street, or maybe even have someone take your picture.
6) PROPERTY ENHANCEMENTS. All home-properties should not only have a save point and maybe a garage, but should also be accessible from the inside. A new wardrobe for each estate would be nice, too, as not all mob bosses walk around in hawaiian shirts. You should also be able to take hookers with you into your estates.
7) GANG ENHANCEMENTS. Gangs should have more of a purpose than just to walk around and shoot at your gang. You should be able to ally with or go to war with different gangs, and it should show in the gameplay. Rival gangs should try to kill you when they see you, while allied gangs should help you whenever you're being chased by other gangs or the police. Also, the police should be considered a gang, and if you're allied with them (would be a special alliance that you get w/in a storyline), they shouldn't bug you if you commit a few crimes here and there.
8) POLICE ENHANCEMENTS. Just because you have a star shouldn't mean all police know where you are and that you are a criminal. Stars should be officer-specific, and once you kill that officer, the star should go away, unless of course another officer sees you and radios it in, which should add on to your wanted level instead. It sucks knowing you're going to either die or get arrested just because you accidentally ran over a cop.
9) ABOLISH TIME LIMITS. Time limits just make the game more difficult than it should be.
10) CHEAT ENHANCEMENTS. A few cheats that were noticeably missing are infinite health and infinite ammo. Sure, cheats take away from the chutzpah of the game, but some people just like to run around and cause havoc without worrying about dying or whatnot.