Well Half Life is a legendary game; haven't disappointed me yet, we'll see what comes next with third episode.
Half-Life has a better sci-fi plot and its protagonist is a geeky professor, with a suit; on the contrary to a muscle, steroid-suit-like-alien-technology blah-blah and is pwning poor koreans from the face of the earth.
Gordon Freeman, the name is just great ; )
Crysis MIGHT be remembered for its graphics, but as we all know, in 2 years only or less they will be outdated. Half life ftw!