I've been a member of OKCupid since . . . 2005, maybe? I can say that I've met a lot of great people on there. I met my lover on there about 6 months ago and we've been together ever since. Yes, there are creeps and losers, but there are a lot of great people on there.
I like that site a lot more than the others because you can find out way more info about them there than you can anywhere else. You answer multiple choice match questions and if you choose to make them public, you can see what someone else answered to them. It's really useful.
My boy and I were a 99% match, but from the questions, I could tell he wasn't really ready to settle down, what kind of spiritual and political beliefs he had, whether he was the big or little spoon, and tons of other stuff before we ever met.