[Movies/Books/Games] Protagonist befriends the antagonist?
There's quite a few of them I'm sure. In my opinion they offer the most exciting twists in the plot. Be it in a movie (Like the newest and Fast and Fury movie) or a video game (Indigo Prophecy). Or perhaps in a book. I don't read myself so can't add any comment to that.
Have you seen a movie, read a book or played a game that had the "bad guy" fall in love/become friends with the "good guy" or the other way around? In the end uniting against a greater foe for example?
one of your party members is a part of the grand evil you're out to slay. In the end you end up saving her from being assimilated into the evil, and of course a surprising (and not quite definite) twist at the end.
Saiyuki is a TV show, not a movie, but the "bad guys" are not really that bad.