I'll go with the first things I think of:
1) - Linford Christie winning the 100m in 1992
2) - GB beating West Germany in the 1988 hockey final & especially Barry Davies's commentary "Where were the Germans? &, frankly, who cares?"
Jingoism at its finest.
3) - Derek Redmond being helped round the track by his dad after his hamstring went in the 400m final
4) - Redgrave's "If you see me go near a boat you have my permission to shoot me
" after winning gold in 1996. He, of course, returned 4 years later.
5) - Ben Johnson's run in the 1988 games. Doped he may've been, but it was awesome at the time.
6) - The Aussie swimming relay team air-guitaring in celebration after winning gold in a reference to some American swimmer's comment about "Smashing them like guitars".
7) - The siege at the 1972 Olympics. Nuff said.
8) - Chariots of Fire; Liddle, Abrahams & all that.
9) - Some Korean boxer refusng to leave the ring for what seemed like years after losing a points decision in 1988.
10) - Bob Beamon's leap in the 1968 Mexico games.