A list of horrible date stories,
http://www.datestories.com/

They’re fairly tame, so if that doesn’t float your boat, there’s always the creepy and disturbing http://grouphug.us/ .

And a site where women register cheating boyfriends,
http://www.dontdatehimgirl.com/,
which looks primed to violate a lot of privacy and/or slander laws.