"Most violent game on steam?" or "What should I play?"

Hey everyone!

Today I just took off the cast on my wrist (after 4 months!!) so I want to play something... I've been playing mostly slow-paced/strategy games so I really want some over the top hyper violent game but I can't make up my mind! So please help me!

Here's what I'm looking for:

• Super violent game;
• Preferably an FPS;
• No strategy, no caution, just simple "kill as much people as you can";
• Preferably (but not exclusive to) from already owned games;

My ideas so far:

• Serious Sam (I think I own all of them);
• Painkiller;
• Postal 2;
• Duke Nukem Forever

So to wrap it up... After 4 months of not being able to play a well paced action game I want to play the most fast paced, violent and goriest game you can come up with! I don't want to play a shitty shooter, though... I just want something fun to turn my brain of and see red sprites all over the screen! I'm willing to purchase something but not looking forward to it!

Pleas help! ^_^

UPDATE: Uooohaa! I wasn't expecting so many replies! :o I was trying to reply to each and everyone but soon it became apparent it was a futile exercise! Anyway... Common suggestions seem to include Bulletstorm (it's a bit more expensive then what I'm willing to pay since I have so many great and untouched titles on my library) and a couple of games I already own on xbox (Jericho, Dead Space, etc). Also to those of you who suggests... Hotline Miami IS great but I managed to beat it with a broken wrist (not that I would recommend doing that)!

So the winner is the killing floor, Serious Sam and Painkiller. Simply because everyone says they're great and I already own them (no sense wasting money when Bioshock Infinite is so close)! Thank you very much for all your tips guys! =)