Bob Newhart.
Ennis, in Brokeback Mountain.
Brad Pitt.
Zorro?
(and good one GorillaMan, I had Sigourney Weaver in mind for Dorothy myself…)
Joe Pesci.
Robert DeNiro, in Taxi Driver.
Gilbert Gottfried
Cleopatra
Teri Garr.
Jack, in The Shining.
Chris Farley
The Wicked Witch of the West
Renee Zellwegger.
Norma Desmond.
Whoopi Goldberg (“I’m ready for my mf close-up, Mr DeMille!”
Father O’Malley in Going My Way
Michael Jackson.
Atticus Finch in To Kill a Mockingbird.
Jim Carrey
Al Capone in Untouchables
Keanu Reeves.
Patton?
Gene Levy
The lead in Citizen Kane
Woody Allen
I was thinking Woody for Jack in The Shining 
is the worst person to play in the remake of … anything. Including Jim Carey movies.
Gilbert Gottfried.
Stanley Kowalski.
Jim Nabors: Gooooooollyyyy, Steller…
Gypsy Rose Lee
Camryn Mannheim
Inigo Montoya
Our own Inigo Montoya, of course. 
Count Dracula?
Owen Wilson
Zaphod Beeblebrox