I have a weird habit of going to the cinema at least a couple of times a week, so sometimes I watch something just for the sake of watching.
Me and my friends watched The Happening, because we knew it will be ridiculously stupid and the idea of the wind killing people amused us. "OMG, what kind of terrorists are these?" (woman speaking about lions). The whole audience was laughing.
Epic Movie, Disaster Movie, etc. We know that it's going to suck horribly. But we still watch it.
But I wasn't able to go and watch High School Musical 3, even though my friends wanted to watch it just for the laughs. I still have a bit of dignity left.