A great addition to a great series.
Hitman: Blood Money, to me is the best in the series, drawing on and staying true to all the great gameplay mechanics presented by its predecessors while streamlining a lot of things to make people have to think about what they're doing without making the game frustratingly hard in spots, as well as giving the look of it a very nice graphic overhaul.
The backstory, presented in between missions gives a great backdrop to what you, as No. 47, are doing in the game. The rating system gives you something to work towards, and each missions has multiple ways to complete it, possibly multiple ways to master it, and some ways that are just plain fun/funny.
The game has a decent bit of re -playability due to the number of ways you can go about completing objectives, but unfortunately, once you've found the best way to do something, there's no _real_ reason to go back and do it again.
The weapons are cool but kind of made useless by the fact that, to get a Silent Asassin rating, you pretty much can never use them. Some of them are just downright useless unless you view that game as a straight up 3rd person shooter, as the shotgun and Assault rifle can never be concealed, and the former is pretty much an instant silence breaker.
The missions differ greatly in scope, objective, and especially setting, so there's really no repeats of mechanics other than the fact that you're pretty much always there to kill someone.
The ending is also great and I can't wait for them to continue this series.
If you liked the previous games and haven't given this one a try, do yourself a favor and pick it up. And if you haven't picked up any of them, this is a good place to start.