Toshiro Mifune reportedly turned down offers to play Obi Wan Kenobi and Darth Vader in Star Wars, and I’m glad he did.   That would be like Max Von Sydow having played the main character in The Seventh Seal playing the part of Ming the Merciless in the Flash Gordon remake (actually I think that’s pretty cool! Sydow also played Jesus Christ after all, and then his best role as the creepy spy in Three Days of the Condor).
I have yet to see The Hidden Fortress, but as a kid it was hard for me to watch the Magnificent Seven and the sequels once I’d seen the real thing in The Seven Semurai.  Years later, I came to appreciate the Magnificent Seven as a decent movie in its own right.  Can you name the two actors who were in both The Magnificent Seven and the Great Escape?  And then name the two actors who were in both The Dirty Dozen (which cast one of the two actors in the previous question) and Kelly’s Heroes.