My Five:
1. Shadow of the Colossus, It's a great game that I must've beaten at least a thousand times, and I still love it.
2. Breath of Fire 3, I still remember the day my brother bought this, we played it for hours and ended up beating it within a week.
3. I Wanna Be the Guy, Same reason as this guy:
Mordwyl said:
This has got to be the most irritating game that was ever developed. Each level is cruelly designed to hate and kill you at every opportunity.
4. Half Life series, These games have the be the best FPS games ever made. Sure they're single player, but I've never liked multiplayer shooters.....ever. (And heres to hoping that Black Mesa Source will be released one day.)
5. Phantasy Star Online (Either Episode 1 or 2. 3 and Universe were garbage IMO), These games are just so udderly addicting. It is the only Online Action-RPG that I've seen so far. (other than Monster Hunter)