Halo & Gears - played a small amount of each, but they're not my cup of tea. Any Call of Duty after #4 - just not that interested in the series; I prefer my FPS more like Far Cry. Rocksteady's Batman games - just got Arkham City free with PS+, so that'll soon be remedied. God of War series - I've only played through #2; they seem like solid games though, so I'll pick up that 5 game collection when it hits the UK.
Nearly all of them. Every time I see some "top 10 games of 2012" video, I generally don't have any interest in the games on the list. Same with the GameFAQs top 10. I just don't have much in common with the average gamer today, who is much more focused on action games.