Evolution: the Game
This is awesome! There is a game coming out called Spore (for PC)
Pretty much you guide a cell through evolution until you can become a large, sentient, organism.
"I call Christianity the one great curse, the one great intrinsic depravity, the one great instinct of revenge, for which no means are venomous enough, or secret, subterranean and small enough - I call it the one immortal blemish upon the human race." -