DC's dark knights.
In before the reboot I suppose? :]
Had the sketch up on Tumblr a little over a week ago, [link] [link] been poking at it between my work.
It's actually printed as 2 separate posters, hence the somewhat split composition.
Edit: Stop asking about Huntress, I associate her more with BoP. Otherwise I'd have to throw in Catwoman and another whole whack of characters.