Crysis has one of the most deepest and sophisticated gameplay mechanics in a FPS game. Don't let the pretty graphics fool you. The physics, the AI, the objectives and even the level design blow away 99 % of other video games. Even the story is good. I love the characters of Nomad and Psycho who are no nonsense professional soldiers. Not every game needs a melodramatic protagonist with a troubled past.
Put simply Crysis is an excellent blockbuster movie taking place in one of the most lifelike simulation oriented sandboxes ever.