I would choose Atrocious because he’s such a badass.
It’s a tie between the Joker and Reverse Flash (Thawne)
It varies. My new favorite is Ricardo “The Dragon” Diaz from CW’s Arrow. Such a badass. But, since that show is essentially “Batman Green,” Diaz is essentially the Joker.
Sinestro, Manbat, Bizarro, Bane.
Kneel before Zod!!!
Toss up between the Joker and Lex Luther
Deadshot or Deathstroke
Oh the clown prince of crime Joker or Darkseid. One Joker has no real motive just chaos, which makes him super dangerous than any bad guy and two A guy(Darkseid) that can fight with his hands behind his back is a beast. Joker is the only villain in comic HISTORY that looks death in the face and Laughs. Ha ha ha ha ha
Definitely going to have to be deathstroke.