Let’s see, first we had Highlander. Then we had The Quickening, which some people still don’t like to talk about. Then we had The Sorcerer. Around that time things split into the TV Series and soon after we had End Game.

After that I got too old to keep track, but I hear they’re doing a new one.

So to answer your question, despite the claim of there can be only one, there are in fact many.