I was a member of AdultFriendFinder back in 2001. Though I did meet one woman for sex and a couple other people for friendship... in general I found the site to be an enormous waste of time. They've finally started admitting (in the small print) that the women they advertise to be "in your area" in banner ads all over the place are completely fictional. If you're a straight man, don't expect much from this site. Most of the people you meet there are going to be completely fake, either people posing as attractive women to dupe you into sending pics as happens here, or just to fuck with you, or maybe bots phishing for e-mail addresses so they can send you tons of spam. The only real people you may find will probably be in the chat rooms- which have a horribly obnoxious interface and are always way too crowded. However, don't expect to find anyone like they have pictured in the ads. Most of the legit people are middle-aged, overweight, unattractive singles who can't get dates anywhere else. Perhaps some homely married swingers here and there. You'll also run into girls who are "bi" looking for girls for threesomes to appease their boyfriends. "Lesbians" who are mostly guys pretending to be lesbians to get pictures/videos (funny thing is, I think they mostly get pics from other fakers). and of course tons of married or otherwise committed people looking to cheat on their significant others and get a little something on the side. The ratio of men to women, ostensibly, is about 10 to 1. If you consider that the vast overwhelming majority of female profiles are completely fake, out-of-date, etc. that ratio is realistically probably more like 100 to 1. Old inactive profiles never seem to get deleted, the site isn't especially easy to navigate or pleasant to look at, and don't be fooled by the "free" sign up. Aside from using their crappy chat room, there is virtually nothing you can do for free- not even browse member profiles.
Before it went to being a pay site again, I would have recommended Hot or Not, even though you can't post nudes there. I haven't tried using the site since they stopped being free, but beforehand it was really easy to use and easy to meet people and most of the people there (unlike AFF) were legit.