If you want a stealth game where you can mix with people and with dark sense of humor, this is it.
At the end of each mission, you get a score and a rating, so you can try to achieve silent assassin (the best score) or serial killer (the worst). The music is excellent, it really tells you what is your situation in the game (all right, discovered, triumphant) and random met characters comment on you (smile!!!). It is quite entertaining.
Newspapers telling you how you did are interesting too. You want to mess up just to see the robot portraits they try to come up with (and see how agent 47 might look with hair...). It contains many other articles that might be or not funny.
Hitman uses a lot of cliché about races and sexes (women are not represented at their best), but if you make abstraction of this, well, it is quite entertaining.
Last but not least, sound is really demanding on the computer, so, if Curtains Down crashes, one of the best option is to put the sound acceleration to basic. It helps.
So, yes, this is definitely a good game to play, full of little details to discover or rediscover (there is a mask of the Phantom of the Opera hidden in the Opera of Paris' basement for example). :) It is quite fast to finish (especially if you go for the serial killer option as I did at the end, because I wanted to know the ending of the story), but it has replay values, and there are more than one way to achieve the missions. I just wished we could throw electric toasters in baths just as seen on the concept art... Perhaps in the next hitman?