I have quite a few experiences that still linger in my head...
I still remember when I first booted Hybris and the music hit me, it was totally awesome... It had set the mood immediately and I was all tensed up for the gameplay that was ahead... It's the shooter I still play up to today, every few months...
I've spent countless nights multiplaying with a friend of mine, playing custom levels we cooked up. The volume was cranked up so the neighbours could enjoy the experience as well (KABOOM!!!!!)
Jeff Crammond's GP
The best racer around at that time was GP and I found myself quite often racing the races that had just been held in the GP season... Only drawback was that other cars couldn't be heard...
Stunt Car Racer
The insane ramp level was my favorite in this one... I just couldn't stop hitting the turbo when going down the final ramp before being launched into an incredible drop
Awesome (and again a game from Jeff if memory serves me correct)
Adventure Construction Set
I'm probably gonna be pestered with this
But I loved ACS at the time, just to build crazy adventures and draw naughty icons
I've spent lots of evenings with ACS...