I'd say Javert, but he wasn't evil.

i think a large part of the point of the book/musical is that everyone is 'right' in their own way. Javert never did anything so wrong, he was just following the letter of the law. val jean actually did do something wrong, actually a few things wrong according to the law, but it was all so that he (or his family) could survive. everyone is right and no one is right - that's part of what makes it so deep and interesting.

Well, TBF, an antagonist doesn't always have to be "evil" per se. Still, I'd say the judicial system of France -- and to an extent, Javert is definitely a personification of that. He's so immersed in his role of Monsieur L'inspecteur that he's almost lost his humanity. He means well, but he doesn't quite...get it, really.