Suggestions by @scarecrow13

Grey DeLisle

as Janice Rand in Star Trek: The New Animated Series

Brian Hull

as Pinto Colvig in I Know That Voice

Brock Powell

as Pinto Colvig in I Know That Voice

Brock Powell

as Johnny Yong Bosch in I Know That Voice

Jordan Peele

as Phil LaMarr in I Know That Voice

Phil Vischer

as Rob Paulsen in I Know That Voice

Will Ferrell

as Max Taber in One Flew Over the Cuckoo's Nest (2005)

Kyle Gass

as Charlie Cheswick in One Flew Over the Cuckoo's Nest (2005)

Jack Black

as Martini in One Flew Over the Cuckoo's Nest (2005)

Jay Baruchel

as Billy Bibbit in One Flew Over the Cuckoo's Nest (2005)

Gary Farmer

as "Chief" Bromden in One Flew Over the Cuckoo's Nest (2005)

Fred Savage

as Billy Bibbit in One Flew Over the Cuckoo's Nest (1995)

Michael Richards

as Max Taber in One Flew Over the Cuckoo's Nest (1995)

Jason Alexander

as Martini in One Flew Over the Cuckoo's Nest (1995)

Michael Keenan

as Charlie Cheswick in One Flew Over the Cuckoo's Nest (1995)

Russell Means

as "Chief" Bromden in One Flew Over the Cuckoo's Nest (1995)

Laura Linney

as Nurse Mildred Ratched in One Flew Over the Cuckoo's Nest (1995)

Jim Carrey

as Randle Patrick "R.P." McMurphy in One Flew Over the Cuckoo's Nest (1995)

PewDiePie

as Producer in Horribly miscast

Patton Oswalt

as Eric Bolling in Political Pundits