Best game I have played on the PS3, by a mile
This game is the best experience I have had on the PS3, bar none. The story telling is so engrossing and emotive, the script and action so engaging, they could turn this game into a blockbuster movie with little to no effort at all (and I hope they do).
The only reason I give this a 9, rather than a 10 is that I feel that the replay value is relatively low due to a great deal of the enjoyment coming from the suspense of not knowing what is just around the corner and what direction the story is going to take you. This is very similar to why it is difficult to enjoy a great movie quite as much the second time around.
Nevertheless, you owe it to yourself to play this game. Do it, do it now!