The Pianist. Wladyslaw Szpilman (Adrien Brody) is still himself, everyone else are muppets.

Salò. The sex worker who tells the stories.

Schindler's List - Schindler

Dredd - Dredd

Master and Commander - take your pick

The Wolf of Wall Street - Jonah Hill

Martyrs, but only if everyone but Mademoiselle's Society members are real

ohh The Fall (german hitler one) keeping Juliane Köhler, and making everyone else muppets would be a statement on its own

LotR - Sauron (or Legolas)

Dune. Keep either Patrick Stewart, or Sting. Not sure which would be funnier.

Repo: The Generic Opera; Nathan

127 hours, but I pick both the girls.

Edit:

Or Lord of the rings... Obviously I choose Gimili.

Star Wars: A New Hope. C-3PO.

Conclave, carlos diehz

Se7en, kevin spacey

Stargate, jaye davison

Star Trek beyond, Chris pine

It's Predator obviously, and keep the Predator...!

Army of Darkness (keep Bruce of course)

Fear and Loathing..keeping Depp/Thompson

Inglorious bastards and the bear jew.

Wayne's world. Garth

Yeah, I was thinking either keep Jaws or the Mayor

District 9. Leave Wikus in.

Hereditary and keeping the guy playing the dad in the family.