Just might be Answers.com. I'd guess 50% of the answers I see there are either flawed or pure nonsense. Here someone asks what the most three-point shots made in a University of North Carolina home basketball game is, and the "top" answer is that once Donyell Marshall hit twelve in an NBA game!
What's interesting is the Answers.com clearly intended to take advantage of the "wisdom of crowds" in the same way that Wikipedia does. So why are Wikipedia's results so much better? I'm just guessing at this point, but I'd say it's the editing. On Wikipedia, nonsense quickly vanishes from the main article (although of course it lingers in the history files). I don't think Answers.com provides a way to make a bad answer disappear.