Wonder Woman, more than anyone else but Superman, deserves a film. However, I can see how an Aquaman movie played straight could be one of the most epic Comic Book movies, especially since, as a character, you can shape him the way you want without a huge backlash.
Wonder Woman and Flash, I'm not a WW fan so I honestly wouldn't really care about a movie about her but she's way too iconic to not have had a film at this point. I voted Flash because he's my favorite character on the list. Wouldn't mind seeing a GL reboot or an Aquaman movie though.
Etrigan the Demon
Wonder Woman (Done in a Clash of The Titans way but better, with Scott Snyder or JJ. Abrams directing. Script by Joss Whedon.
Deathstroke. Surprisingly I would let Quentin Tarentino have this one. Make the duels like Kill Bill, but the story a dark crime dramedy like Jackie Brown or Pulp Fiction. Slade gets hired to steal about ten million dollars worth of Diamonds, but a team of world class cat burglars, knew about Slades hit, and they manage to use him to get the stash. Now in order to achieve his objective, And preserve his reputation he has to track down each member of the gang one by i.e. and each member is a specialist, in a different field. One chick works for the CIA as a spy. One dude is a techy, who's frickin house is like a deathtrap. One dudes a ex Navy Seal who opens a Taekwondo Dojo.