NT has weak tastes in gaming, lmao at putting HALO anywhere short of 5th. :p
Anyway, my list:
1. Half Life saga. (PC)
2. Metal Gear Solid series (all consoles)
3. Team Fortress 2 (PC)
4. Counter Strike Source (PC)
5. GODLO series (Halo) (PC, Xbox, 360)
6. Grand Theft Auto series (all systems)
7. Day of Defeat Source (PC)
8. Battlefield 2 (PC)
9. Pokemon (handhelds)
10. Portal (PC)