As someone who's spent most of the last 14 years playing games, I'm gonna have to try and keep it short :p
1. Croc: Legend of the Gobbos, first game I played when I was seven, definitely deserves a mention, although Croc's death noise still haunts me to this day.
2. Pretty much the entirety of Final Fantasy IX, such an awesome game. Beautiful storytelling and characters.
3. Leaving Dr Kleiner's lab in Half Life 2 and seeing all the combine forces come out of the citadel - so epic.
4. Playing Micro Machines V3 with my dad as a kid, and the ridiculous rivalry we had.
5. Getting the crap scared out of me in Amnesia: The Dark Descent, specifically the prison, the Choir and Storage. If you've played it you'll know what I mean :p
6. Pretending to be a military genius in Medieval: Total War.
7. All the good times on Team Fortress 2 and CSS, before I got bored of 'em.