Probably the best crazy girl story I've got involved a girl coming into my house uninvited and unknowingly (my door wasn't locked but still), her throwing herself on me and saying "I have to be with you, I can't stop thinking about you" after I ended things with her. I've dated some crazy broads too and I'm sort of disappointed that's the best I've got.
I don't think she was bi-polar, just crazy. I do chalk up being told I'm good in bed to me being bi-polar sometimes, however. And definitely the best sex was when the emotions were the most intense which tends to come out with girls I have the best connection with. I dunno, the bi-polar thing sometimes just makes everything seem more intense, which def does translate into better sex I'd say.