Lord of the Rings (I suppose is a classic by now) Ian McKellen is still Gandalf (a la Michael Cain) and Sauron is muppetfied
Kermit = Frodo
Fozzie Bear = Sam
Gonzo = Merry
Rizzo = Pippen
Ms Piggy = Eowyn
Animal = Gollum
Doctor Teeth = Gimli
Janice = Legolas
Beaker = Arwen
Doctor Honeydew = Elrond
Swedish Chef = Saruman
Sam the Eagle = Faramir
Rowlf = Aragorn
Sweetums = Theoden
A bit anticlimactic: it tasted of nothing, even though it smelled bad.