Gonna try my best and name all the people from left to right:
Manbat, Shiva, Talia, Ra's al ghul, Harleyquinn, Bane, Black Mask, Hugo Strange, Catwoman, Joker, scarecrow, Deadshot, Deathstroke, Riddler, Twoface, Hush (great graphic novel illustrated by Jim Lee, if you haven't read it go buy it. Its so worth it) , Penguin, Killer Croc, Red Hood, Mr Freeze, Clayface, Phantasm (from the animated series movie Mask of the Phantasm), Poison Ivy, and Victor Zsasz