Simply one of the best games ever, hands down. Incredible.
You can choose to run and gun, which is super fun considering the game offers a huge array of weapons, a handful of which are customizable to an incredible point (laser sights, extra ammo, silencer, scopes, ammo, butt stocks, full-auto fire adaptation and more). The game isn't meant to be played this way but it's interesting enough with all the wacky physics in this game. Nonetheless a good run and gun is fun enough, but usually after you've beaten the missions, the right way.
What I mean by the right way is of course, stealthy. The Hitman franchise is notorious for having so many different ways to do missions as stealthily as possible. Just as an example, and this is in the game so if you don't want to read this part don't, you can grab a bottle of aphrodisiac, put it in your targets drink, he then proceeds to want to go have sex with a woman, after they have sex he goes to smoke a cigarette on the balcony, in which case you push him off the balcony, making the whole thing look like an accident. How cool is that?
There are so many fine aspects to this game, such humor, and yet, such freaking awesomeness, that it's hard to ever stop playing. If you have never played this game you should go buy it right now and not leave your room for a week so you can try and do everything you can possible do, and even then you wont complete it all.
Best third person game ever.