Far as online quizes go, the ones at
http://www.thespark.com are pretty much the only ones I ever actually enjoy taking. I recommend those to anyone who doesn't get easily offended and is okay answering some pretty personal questions (*parental advisory*

). Try their IQ test and tell me how ya do.

(Please, no one spoil this test if you've taken it already, COUGH)
Otherwise, I find online quizzes to be dull and pointless (cough, emode.com) for the most part, although I HAVE taken some very nice ones... A few "aura color" tests and one or two psychology quizes actually turned out shockingly well! I'll post those if I can find them, doubt I will, though.
Otherwise, it's just the occasional "fanboy" quiz for me, such as the ones featured here, even if those fall into the "blatantly obvious quiz" category that I usually avoid.