Gauntlet, without a doubt, if you have a 4-player CP. Cooperative-competitive games like Gauntlet (Quartet, for instance) always go well.
Super Sprint/Championship Sprint (with or without spinners - joysticks work fine, just like on the C64), Iron Man Offroad Racing, Indy Heat, that sort of game. Head-to-head racing games are always good - I remember pouring coins into Final Lap (and sequels) because of this.
Double Dragon
Galaxian
Pac-Man
Ghosts'n'Goblins/Ghouls'n'Ghosts
Bubble Bobble
Generally, games that have weird end of turn/game sequences are good (especially if they are random), stuff that make people laugh, games that non-experts cannot hog machines for too long always work well. Tetris, regardless of how wide its appeal is, allow people to hog a machine for too long (at least if I play...)