So far I have Bubble Bobble, Columns, Fantasy Zone the Maze, Spy vs. Spy, Time Soldiers, Gauntlet, Double Dragon, Rampage, California Games, Reggie Jackson Baseball, Great Baseball, Slap Shot, and Gangster Town.
For two-player alternating, I have Fantasy Zone, The Ninja, Black Belt, and Ghost House.
Are there any good two-player games I don't have yet? (I'm not willing to shell out the big bucks for Street Fighter.)
I'm especially interested in finding more 2-player simultaneous, non-sports games to play with my girlfriend; she likes the first four games listed.