Dumas' The Three Musketeers (novel and films)

My favorite version--after reading Alexandre Dumas' classic novel The Three Musketeers--to watch: Richard Lester's version (scripted by the author of the Flashman novels!)--

https://www.youtube.com/watch?v=_-LfUtHnEBY

But then you'll also need to watch Richard Lester's sequel (though part of the original French novel):
The Four Musketeers--

https://www.youtube.com/watch?v=rMhwGUGNuxI