which one is better???

Crysis 2, easily. Black Ops, well, it was just as bad as any other CoD. Halo Reach was huge disappoint to me. One of the worst maps ever made (Fortunely community maps have started flowing in to matchmaking), lack of good story and characters, worst music of the series and so on. It was ok though. Crysis 2 is great, but bad netcode makes me not want to play that game at all.

Crysis two man. Black ops was so freakin' boring, and Halo reach I still plan to play, but it would NEVER beat Crysis.
Crysis dominates on sooo many levels.