1. Half-Life 2 - PC
2. ArmA 2 - PC
3. Thief 2: The Metal Age - PC
4. Trackmania United - PC
5. GTA 4 - PS3, 360, PC
6. STALKER: Shadow of Chernobyl - PC
7. Elder Scrolls 3: Morrowind - PC, Xbox
8. Fallout: New Vegas - PS3, 360, PC
9. System Shock 2 - PC
10. Metal Gear Solid - PS, PC
I've been gaming since I was born pretty much. Started out with a Genesis, then a 64 and a PS1. Discovered the joys of mods and PC gaming when Half-Life came out. Still am a PC gamer, though I enjoy some PS3 once in a while. Never owned an Xbox, probably never will.
Updated for the end of May, 2014:
1. Half-Life 2 - PC
2. Starcraft II - PC
3. ArmA 3 - PC
4. Trackmania 2: Stadium - PC
5. Microsoft Flight Simulator X - PC
6. Counter-Strike: Source - PC
7. Thief 2: The Metal Age - PC
8. EVE Online - PC
9. Elder Scrolls 3: Morrowind - PC, Xbox
10. Metal Gear Solid - PC, PS
4 years later, some things change; and some things don't. :)
Nice list.
Personally,I always preferred Thief: The Dark Project over The Metal Age. I liked the horror/gothic atmosphere of it more than the steampunk one in the second game. Thief Deadly Shadows is also great.
Updated for the end of mid March, 2022. I was 17 when I made the first list; now I'm almost 30. Omitting the platform since most of these are multi-platform nowadays:
1. Half-Life 2
2. Elder Scrolls 3: Morrowind
3. Pillars of Eternity 2: Deadfire
4. Fallout: New Vegas
5. Baldur's Gate 2
6. Lord of the Rings Online
7. DCS
8. Prey (2017)
9. Dark Souls 3
10. Pathfinder: Wrath of the Righteous