Every time Markos posts a straw poll, people complain that one candidate or another isn't included. I'm not really sure why - I'm sure that if, say Al Gore wants to step in, being left out of a single internet straw-poll isn't going to prove to be a drag on his campaign.
In this dKos tradition of bitching about the inconsequential, here's a straw poll of nothing but fantasy candidates.
Also, I encourage you to complain in the comments that I left your favorite candidate out, because this truly wouldn't be definitive if each and every person who isn't going to run isn't included.