Absolution is a neat stealth game that has almost no previous Hitman elements. Worst thing about that game is the story, the story is pretty fucking bad, so the emphasis on it is disappointing. The stealth in Absolution is insanely puzzle like, I had to think of really weird methods to manipulate the AI.
Blood Money is still the best murder simulator on the market. Roleplaying as different hitmen philosophically is what keeps the game fresh. I used to spare innocent lives, in a playthrough last year I capped anyone in the same room with the target or if they were near an item I needed. Killing everyone in a room with a silenced pistol, and no one outside that room noticing, is one of the greatest feelings in the world. No witnesses, no mercy.