I never buy a game I know will be supposedly bad just for the hell of it. I mean, I bought "Kane and Lynch 2: Dog Days" even though most people said it was shit, but I actually enjoyed it a bit. And this is from someone who loathes the idea of regenerating health and cover-based shooting. Yes, the game itself isn't very spectacular, but the visuals and "filmed-by-a-cheesy-camcorder" filter are.
Although, I must admit that one game I would love to try is the abysmal "Big Rigs: Over the Road Racing". Just because it is the worst thing ever made. YouTube it. Just to give you guys an idea, there are no collision physics, even for a bridge you have to pass over, meaning you actually drive in the valley underneath it and you go the same speed in reverse as you do going forward. Oh, and the AI drivers don't move. Honestly.