My top five games of all time (ALL games not just AVN's) is probably:
1) Skyrim
2) Mass Effect 2
3) HALO Reach
4) Eternum
5) Absolver
Sure the list excludes impactful games like Tetris and Mario, and leaves out franchises like COD, but in terms of pure enjoyment, story, and engagement i felt while playing them, Eternum earns its place.