Vingt Ans Apres (Twenty Years After)
First of all, I haven't seen this movie. But I enjoyed The Three Musketeers (especially because it seems to be the closest to the book of any movie). When I read the plot summary, it looked like this was based on Vingt Ans Apres ("Twenty Years After" in English - the first sequel in the series), but Milady's son turned into her daughter.
Aside from that, how close does it stay to the book?