Don't believe the negativity...
Prior to the DX11 patch I was annoyed with Crysis 2 because it was so much of a console port. Running liquid cooled SLI I was unable to play Crysis 2 on both GPU's. Since 1.9 patch & DX11 that has changed. Crysis 2 now runs in SLI with no random blob shadows. The game looks stunning and actually the single player campaign is fun. Those who say it is no longer Crysis... Absolute nonsense. The core Crysis gameplay remains it's just the location that's different. The city is quite stunning to behold especially at night with glowing neon signs and rain socked streets. I have reached the point in the game where the city is transformed into an alien ravaged one. The cut scene leading to this point was stunning. Very cinematic. I've also played some of the multiplayer too, it's fun and that too looks great in DX11 and with nice audio as well. Some have complained that the story is poor. Why? It's not a blockbuster scifi script but it is interesting nevertheless. The character modelling and acting is impressive to behold. The characters are so lifelike and their movements so realistic they are able to convey some degree of emotion. All in all I would say this game is cutting edge on a PC in DX11. No other game looks this good.
EDIT: Some weeks on from purchase and I am still playing the single player campaign. It's massive! The length of the campaign is impressive. I've updated to the latest 1.9 patch and DX11. There is a performance hit but the graphics are very nice. I'm running dual 560Ti liquid cooled SLI. I would say crysis 2 is one of the more interesting games I've played this year.