Maybe the Godfather.
Michael Corleone becomes a worse and worse villian.
In the beginning he just tries to defend his (criminal) loved one.
Later on he takes revenge on anyone who has ever crossed him. Also “justified” less and less by the excuse of self-defense … until he is eliminating helpless former enemies like Carlo (and in the next episode Fredo).
By Godfather III he is looking to repent of his many sins … which possibly turned off Godfather I and II fans … but he is less of a villain by then. Less of an anti-hero too.
It’s a favorite of mine due to the fact that its a great movie though … not the FACT that the villain wins.
Michael Corleone is the protagonist though … the one you follow … and not the antagonist (the usual villain role). Surrounded in a world of competing villains some may not even consider Michael a villain. But he is. Or was.
He “won” by killling all his adversaries in quite a different way than Gary Cooper killed HIS in High Noon for instance.
Presumably becoming de facto “boss of all bosses” per the bloodbath.

His subsequent “struggles”
- to become “legitimate” in G-II and to
- get out of the mafia and be “forgiven” (by God and the Church before he dies) …
don’t quite make Michael “not a villain” per excusing each evil he commits (IMO).
By the end of the Godfather (I) he was definitely a villain … even if not the only one.