Need help with a crisis

I'm looking for a new fps and I've narrowed it down to two games: Crysis and Crysis Warhead. I've heard good things about Warhead's multiplayer and improved engine, but it's much shorter then the original. Which one do you think is better?

To be frank, I found Crysis and Crysis Warhead to be absoluetely terrible games. The gameplay was very shallow and the whole "sandbox freedom" thing was overrated. The maps are huge, but you're forced down very linear paths by cliffs and oceans full of man eating sharks.

If you're looking for a good FPS I would have to recommend the STALKER series. They're underrated games and can be a bit buggy at times, but Clear Sky looks incredible and plays very nicely. Apart from that, if you haven't already, buy the half life series off of steam. Best FPS in the history of gaming.