Suggestions by @doncorleone
994 suggestions

Alan Ruck
as Flash in 80's Justice League fancast (please read synopsis)

John Cusack
as Joe Biden in Trump

Daniel Craig
as Hawkeye in New Avengers in UCM

James Marsden
as Shazam in DC Characters

Daniel Kaluuya
as Green Lantern 2814.3 in What if the DC universe was rebooted

Liev Schreiber
as Ben Grimm in Rebooted Characters

Ken Watanabe
as Mr. Miyagi in Rebooted Characters
Camren Bicondova
as Worst TV in Best & Worst Superhero Castings

Guillermo del Toro
as Director in The Dark Knight Remake

Kevin Bacon
as Jim Gordon in The Dark Knight Remake

Eva Green
as Rachel Dawes in The Dark Knight Remake

Michael Fassbender
as Harvey Dent in The Dark Knight Remake

Karl Urban
as Batman in The Dark Knight Remake

James Franco
as Joker in The Dark Knight Remake

Arnold Schwarzenegger
as Elder Price in The Book of Mormon

Seth Rogen
as The Cat in the Hat in The Cat in the Hat (Remake)

Bill Hader
as The Cat in the Hat in The Cat in the Hat (Remake)

Michael Shannon
as Norman Osborne in Marvel Cinematic Universe

Kim Basinger
as Wonder Woman in 80's Justice League fancast (please read synopsis)

Dan Aykroyd
as Steppenwolf in 80's Justice League fancast (please read synopsis)