Darn, knew there'd be some C64 stuff at least I'd missed, thanks to Dr Bong for the inspiration.
International Karate-a firm 2 player favourite at school this one, personally I always preferred it a tad more than the sequel IK+.
Even if I could never quite complete the duck/jump knives/spears bonus sequence,you could always make up for it with breaking the boards.
Summer Games & California Games-altough Summer Games had a touch more simulataneous 2 player action,each brought out the best in multiplayer action. Toughest events always had to be the "impress the judges" of the diving platform/surfing events.
Pitstop 2-like the above games, always (for me at least), set the "standards",by which all subsequent games of these types were judged by,especially in terms of "pickup playability"