Deus Ex: Invisible War
Honestly this is one of the best games that I have ever played. Its kind of like fable, in that throughout the game you make choices, only it's a first-person shooter. The game is actually really challenging when you put it on the hardest setting. You play as Alex Denton, a human with biomods. Basically biomods can make you stronger, faster, self-healing, invisible, you name it. Building up strength early is cool cuz you can go through the game simply throwing boxes, barrels, etc., at people and killing them. The storyline is very well developed, the graphics and sound are very good, and the gameplay is addictive. It is a pretty lengthy game, but after you beat the game, you'll still crave more. The game definitely has replay value. I've played through the game 7 or 8 times now. I can't wait until Deus Ex 3.
Few games have been as perfect, and the Deus Ex series is one of my favorite series of all time.