I think I got you all beaten (except maybe one or two) on oldest game played on oldest system:
"Punchy" on the Commodore 16 (16, not 64 heh). It's a left-right platformer (one of the first ever on home computers) where you run across the ramparts of a castle and you have to jump the gaps and avoid archers and so on.
Z and X to move and the Commodore key to jump, lol. It came with the computer. I must have been no older than 7-8 (so that's around 1985).
age of empires. any games older than a 166. pentium were to weak compared to a game counsel, imo. the 1st game i ever played was adventure on the Atari 2600.
some craptacular game called syndicate for the mac. It was like a blend between third person shooter and crap. I dont even know how to descirbe the game. Anyone else ever played it?