And Doctor Who, specifically playing the Minotaur in The Time Monster.
Actually, there's a funny anecdote about his role in the original The Hitch-Hiker's Guide to the Galaxy TV series (there's apparently a new TV series being made). During rehearsals, David Learner, the man who played the body of Marvin got to talking with Prowse, and asked him why he thought George Lucas overdubbed his voice with James Earl Jones. Prowse replied, in a West Counties accent, "Oi have no oidea."
I was reading in his obituary that he apparently got totally screwed by Lucas and company during the filming of Return of the Jedi when they thought he leaked details to the press that he wouldn't be playing the dying Darth Vader. They basically threw him off the set and replaced him with his stunt double and neve allowed him to come to Star Wars conventions. Rather shabby treatment.