And it's done. Thanks for running this again Smeags! I always have fun with this and I already know two games that are likely to make next year's list. So, final list:
50. Neverwinter Nights 2 (PC)
49. Unreal Tournament (PC)
48. Final Fantasy VI (SNES, PS, PSN, Android)
47. The Witcher (PC)
46. Wolfenstein: The New Order (PC)
45. God of War III (PS3)
44. Gran Turismo 5 (PS3)
43. Starquake (Amstrad CPC 464)
42. Bioshock Infinite (PC)
41. Assassins Creed IV: Black Flag (PC)
40. Tomb Raider/Tomb Raider Anniverssary (PS1, PC)
39. Tekken 3 (PS1)
38. Shadow of the Colossus (PS2)
37. Gran Turismo 6 (PS3)
36. Metal Gear Solid 4 (PS3)
35. Age of Mythology + Titans expansion /Age of Mythology: Enhanced Edition (PC)
34. Bomb Jack (Amstrad CPC 464)
33. Call of Duty (PC)
32. Final Fantasy X (PS2)
31. Portal (PC)
30. Starcraft (PC)
29. Fallout 3
28. Portal 2
27. Neverwinter Nights (PC)
26. Starcraft 2 (PC)
25. The Elder Scrolls III: Morrowind (PC)
24. Dishonored (PC)
23. Assassins Creed II (PS3)
22. Call of Duty 4: Modern warfare (PC)
21. Metal Gear Solid 3: Snake Eater (PS2)
20. The Witcher 2 (PC)
19. Age of Empires II & The Conquerors expansion (PC)
18. Legend of Zelda: Links Awakening (GB)
17. Metal Gear Solid
16. Grand Theft Auto: San Andreas (PS2, PC & Android)
15. Uncharted 2 (PS3)
14. Star Wars: Knights of the Old Republic (PC)
13. Half-Life, Half-Life Source & the Black Mesa mod (PC)
12. Age of Empires & The Rise of Rome expansion (PC)
11. Grand Theft Auto V (PC)
10. Mass Effect 3 (PC)
9. Elder Scrolls V: Skyrim (PC)
8. Final Fantasy VII (PS1, PC)
7. Super Mario World (SNES)
6. Elder Scrolls IV: Oblivion (PC)
5. Dragon Age: Origins (PC)
4. Mass Effect 2 (PC)
3. Deus Ex: Human Revolution (PC)
2. Half-Life 2 & Episodes 1 & 2 (PC)
1. Deus Ex (PC)