Good Enough?

Let's talk about expectations in the dating world, specifically our expectations for who and what a potential partner is.  I'll cut to the chase here and say that I'm in the catch 22 of not feeling good enough for the men that I like, but being unable to find a "lesser" possibility attractive (and I've tried!)  I did some googling on this issue and it seems that much of the available wisdom on this topic is directed at men who need to be more confident to land and have sex with higher quality women, but while that advice might give me the inside track to the male's evolutionary "role" in relationships, it isn't helpful for me.  What can I do to be more attractive to the kinds of men I want to be with?  It's not that I can't find attractive men who want to have sex with me (I typically don't), it's that my dream guy wants his dream equal and I don't fit into that category.  This isn't said in a self deprecating way, but rather out of a desire to find happiness and the realization that when I do occasionally find someone I really like, I've started to look for the caveat (married or otherwise unavailable).  I don't hate men by any means, but I've noticed that unavailable and/or asshole guys tend to be attracted to me, and it's made me more suspicious.  Is there really such a thing as not being good enough?