Firstly, the game is beautiful. The foliage, breakable objects, and sense of time all provide a fairly realistic experience.
Truly, my screenshots do not do it justice! Be warned, this game is a known resource hog.
One thing I really like about it, the foliage in this game is actually useful!
But by far the best reason to own Crysis, and now Crysis Warhead is....
MechWarrior Living Legends!
Take the crysis game engine, and make everything a 30+ ton robot with a person inside controlling it--then you have MechWarrior.
(don't let the screenshot fool you, the game is truly beautiful)
Here we have a friendly-looking novacat about to be harassed by two shadowcats.
One rich dude who owns a giant
robot battlemech against another--the way it should be!