I rather liked Kane and Lynch.
It made for a great rental. I didn't have a chance to go through it all co-opsie, but I'd bet its pretty good for that. I liked playing a shooter that appeared as if it could conceivably take place in the real world, some of the levels were outstanding (

disco shootout

), and I liked the uncompromisingly bleak story and nasty characters.
as a gamer geek bonus. The guy who voices Mario is Lynch, the wife-beating/killing, profane, violent-prone psycho. That's kind of awesome.
as its content challenged, and I'm guessing nobody is playing the actually sorta good multiplayer anymore, paying 60 bones for it would not be a good use of funds. But at a cheap price, I'd say its well worth it.
But that's just me talking. I'm not with mainstream opinion, but I dug it plenty.