So according to the poll results so far, Blue Beetle and Ms Martian are leading by a good margin (10+ votes). Can't say I'm surprised! They're pretty much associated with the the team, despite never being a member in the comics, thanks to the highly regarded animated series of the same name.
What is surprising to me is that Aqualad is barley hanging onto third as Aquagirl, Bunker and Empress are all less than 5 votes behind him. Maybe it's because he's already on a team while the other three have been stuck in limbo for years?