Not in any particular order, I cherish these moments:

The whole final dungeon of FF8 is really fun. It's well designed with nice puzzles and bosses. I really like what Ultimecia's done with the place.

The first time I ever successfully buffered Summon Suffering in Soul Calibur 2 on a human opponent with 66B+K. Aweeeeessssooommmme.

Crash Team Racing, pwning Oxide. Hah, my go-kart beat your spaceship! Man, I love that game.

Need For Speed Underground, pwning Eddie's posse in the final few showdowns. I know they're easy (for some weird reason) but that just makes it so much better. Also driving Samantha's Civic makes me warm and fuzzy inside.

The Bouncer. Landing Wong's unblockable on anyone is cause for lots of laughs.