I think comparing anything like RE5/Dead Space to Crysis is wacky. I'm desperate to play RE5, though. But I can't buy it till I finish 4, which I've been really slacking on. So the pox on you for having played it and enjoyed it!
About which patches to get for Crysis, I'm not sure. I got in on release and ploughed through it that night. Had to remove due to shrinking hdd space. I would imagine that the EU/UK version will reject incorrect patches, and the latest one is most likely cumulative. Have a punt!
The thing about Crysis/Warhead is that is really pays to be creative. A great game and if you make full use of your suit it's heaps of fun. You don't have to play it any certain way, and on a whim deciding to creep around an encampment because you fancy strangling and tossing someone over a roof is not frowned upon, neither is death by kitchenware. Enjoy.