I'm totally on bored with Metak gear solid, the PS1 game, that was all kinds of awesome, from the movie like opening credits to the brilliant 'Hal and Dave?' bit with the Otacon ending.
Aeris' butchering by sepharoth, still the best badguy in a game was a shock, but i thought the scenes when you visit the original cloud's home was the best twist in the game.
Two that haven't been mentioned that I love,
the T-Rex in the first Tomb Raider Game,
Playing SSF2Turbo, the first time I took a round off stephen Hillan, in a Ken V Ryu match, the guy was just amazing at the game, in nearly 20 years the best guy i've ever played against, and the guy who showed me how to accurately dragon punch when you wanted to.
Actually, the first time you pull that move off when you need it is a pretty memorable one