Suggestions by @lazystudios

Shayne Topp

as Booster Gold in DC Extended Universe Reboot

Christopher Briney

as Red Hood in Casting James Gunn's DCU! :D

David Dastmalchian

as Batman in DCU Cast

Aubrey Plaza

as The Joker in Batman Villains

Christopher Briney

as Jason Todd in Batman Villains

Cory Michael Smith

as The Riddler in Batman Villains

MatPat

as The Riddler in Legion Of Doom

Christopher Briney

as Harry Osborn in MCU Rebooted

Lars Eidinger

as Brainiac in James Gunn's DCU

Aaron Pierre

as John Stewart in James Gunn's DCU

Kyle Chandler

as Hal Jordan in James Gunn's DCU

Jason Momoa

as Lobo in James Gunn's DCU

Matthias Schoenaerts

as Krem of the Yellow Hills in James Gunn's DCU

Milly Alcock

as Supergirl in James Gunn's DCU

Michael Rooker

as Red St. Wild in James Gunn's DCU

David Denman

as Captain Triumph in James Gunn's DCU

Anthony Carrigan

as Metamorpho in James Gunn's DCU

Nicholas Hoult

as Lex Luthor in James Gunn's DCU

Isabela Merced

as Hawkgirl in James Gunn's DCU

Nathan Fillion

as Guy Gardner in James Gunn's DCU