I prefer the original over Warhead or Crysis 2.
I agree with HEXiT in that not everybody isn't going to like the same thing.
I like games that let me set my own pace and choose a combat style, and I think the first game gives you the most flexibility in that approach. I think the story was "good." It didn't suck me in like FEAR or Metro2033, but it was certainly more interesting to me than anything from the BF or COD camp. It was good enough to keep me glued to the computer through most of my first play-through.
Crysis 2, when judged by itself and not compared against the original, is still a great looking, fun game......but, IMO, they totally ruined the mechanics that made the first one so good. Totally dumbed it down with the gutted suit functionality and lack of movement options. It feels sloppy, laggy, and not at all like CRYSIS. The fact that they also dismissed most of the characters established in the first games really disappointed me and kind of detached me from the storyline as well.
I really wish 2 would have been more of an extension of the original, and not a complete abandonment of it. Ah well...I guess that's the direction they felt they needed to go - - I realize some people like that style of game-play more.
I feel this way about the MP side as well. Count me in as one of the guys who loved Crysis Wars. Huge maps with tons of different vehicles and weapons. It was a lot of fun while it was active, and required a lot of skill to do well in. I think it was a good mix of the fast, twitchy Counter-Strike style of gameplay with the more realistic weapon handling of a game like BF.