In San Andreas, you can make fellow gang members join you in whatever you're going to do. But they're all idiots. If anything, they make gang wars more difficult. They like to walk in front of me while I try to shoot people from other gangs.
The enemy gangster AI isn't that great either. They like to run in the opposite direction for no apparent reason.
In the PC version, there's a little bug that occurs whenever it rains. It mutes all sound except for the radio. There is supposedly a patch to fix this, but if I use it, I won't be able to play the San Andreas Multiplayer mod.