Without a doubt, the best Hitman game. They really hit the stride with this one.
The sequel improved the formula, and contracts was decent, but with BLood Money, Hitman really comes into its own.
They nail everything: the graphics, the story, the locations, weapons, targets, everything. And going through a mission, observing the ins and outs of a location and setting up traps and kills is more fun than ever, thanks to a more balanced enigine that allows to shoot your way out of a sticky situation.
Theoretically, you can blast your way through all of the levels guns blazing, but this isn't ideal or nearly as fun. But if you make a mistake during a mission, its a relief to know you can blast the guards then run rather than completely start over from scratch. You wont get as high a score, but at least you'll progress.
Definitely one of my favorites, I'm looking forward to the next installment.