Per Danny DeVito references above:
Taxi cast
Reverend Jim---Legolas
Louie DePalma---Gimli
Latka/Vegas Vic--Smeagol/Gollum (my favorite casting)
Alex---Aragorn
Tony (Danza)---Boromir
Nardo---Eowyn
Simka---Galadriel or Goldberry (picture Carol Kane in her role as one of the ghosts in the movie Scrooged)
Princess Bride cast
Gandalf---Miracle Max
Eomer---Inigo Montoya
Fezzik (Andre the Giant)---Treebeard
Saruman---Vizzini
Arwen---Princess Buttercup
Elrond---Peter Falk (the grandfather role)
Mouth of Sauron---Count Rugen
King of the Dead---Prince Humperdinck (well, they were both a bit
not overly brave)
Wormtongue---The albino