To be honest, Crysis is the only game so far which has lived up to its own hype (well, along with UT3 as well). CoD 4, while it features beautiful graphics and art assets, is too linear, and Bioshock, while heavily original, didn't captivate me as much as I would have thought. Although Bioshock was extremely interactive, it simply wasn't engaging enough to be a Half-Life 1 or 2 buster for me.
And Enemy Territory...talk about a massive let down in of itself. I've been looking forward to that game for years and what does it turn out to be? A generic sci-fi MMOG arcadefest. Nothing new here folks, keep moving... Don't even get me started about Perseus Mandate, which is essentially a regurgitation of F.E.A.R. 1 with a nonsensical storyline. I honestly believe that the developers of Perseus Mandate have given up on any kind of coherent story, and instead thrust you back into the all too familiar urban landscape for another walk in the park so you can blow the hell out of people/things with a rocket launcher.
/endrant
Also have yet to play Assassin's Creed, which looks incredible from what I've seen, but will it also live up to its hype or fail outright?