1. The Orange Box
2. Half-Life 2 (my #1 that year)
3. Red Dead Redemption
4. The Witcher III: Wild Hunt
5. Batman: Arkham Asylum (my #1)
6. DOOM
7. Shadow of the Colossus
8. The Elder Scrolls V: Skyrim
9. Bioshock Infinite
10. The Walking Dead (my #1)
11. Super Mario Odyssey
12. Gears of War
13. Marvel's Spider-Man
14. Mario Kart 8
15. LittleBigPlanet
Half-Life 2 is the best individual game listed, but when you bundle it with Portal, Episode 1, Episode 2, etc...
I love every game 1-7. Games 8-11 are great but with some real serious flaws. Games 12-14 are fine, but not really my thing. LBP is the only game on the list that I really did not like.