Singularity was pretty cool. I tend to get easily bored with FPS games and with Singularity, I initially gave up due to boredom, but that was right at the point just before it got interesting. Luckily I gave it a another shot and after getting the TMD, I couldn't put it down until finished.
Bulletstorm was fun.
I'm yet to play Rage and haven't really gotten into my PS3 yet to start playing the other two.
Crysis is one game that I just can't get into. I don't know why. Perhaps I'm getting too old and the game too complicated or something, but I just have no interest in the game.
Even though I can't stand FPS games anymore, other games that did interest me though, was Fear 1 and 2 and Half life 2.