PC GAMES:
#1: Half-Life: This game gave me more multiplayer hours than any other FPS, and the story's pretty good. The fact that you never leave Freeman's body crafts a realism never seen with the likes of Halo, Metroid Prime, etc.
#2: Fallout 2: Well, this HAS to be on my top 10 PC games. The reason it's not #1 is because it's too linearised.
#3: DOOM: Well, not much to say here. Very good FPS. Kicks the crap out of most newer ones.
#4: Fallout: No other CRPG has ever convinced me to go so long through it. It's the frst one where I actually want to hit the level cap.
#5: Quake II: Good single-player experience, only FPS where I'm not a noob or semi-noob(indeed, I'm a mid-ranked player). Multiplayer experience kicks ass, and some of the best game music ever.
#6: Command & Conquer: Red Alert II: Brilliant RTS, good experience of control.
#7: Worms 2: Well, just good fun all round. It's fun to make your own weapon settings...
#8: Ground Control: This is a good RTS, the battle system works well. Good story.
#9: MechWarrior 3: This is before it became Mech Commander. This is a good FPS/TPS.
#10: AOE II/The Conquerors: This is good, especially the expansion. It's easy to control your troops, but the fact that if you want them to stay put, you have to use No Attack Stance, is annoying.