I love Hitman, always have done, by far one of top 5 favourite video game series'. The latest installment is by far the very best, I would go as far as saying it's one of the best games on the PS3, period. The story is engaging right from the start, the gameplay has certainly improved significantly since Blood Money (see Hitman: HD Trilogy) and is one of the most fun stealth games out there. The Absolution mode (campaign) is brilliant, there are so many ways you can take out your target(s) and get away, the ranking mode has improved significantly with the new ranking system generated through points as opposed to the original shots fired, times spotted malarkey from the previous games.
Contracts mode however is where the game is seriously addictive, I can sit for hours just playing Contracts mode, making up contracts, trying to beat peoples scores, and I have to say I'm pretty good at it. The whole "multiple ways to take out your target" really comes into play in this mode when you can select anyone (literally ANYONE) from a crowd, mark them for assassination, and take them out in any way you see fit. The style you do it in determines how much cash you receive with which you can buy upgrades, costumes, new weapons etc. I once walked into China Town, picked up a fillet knife, threw it at the guys head and left without being spotted, got $300k for it...it's amazing.
Thing is I can talk all day about how great this game is, basically you should just me the time and buy it.