ROTS: Emperor’s revenge against Windu.
SW: Vader’s fight with Obi Wan.
ESB: Vader chamber scene or the reveal scene.
ROTJ: Emperor scenes and Vader’s death scene.
RO: Vader scenes.
Honourable mentions: Vader vs Ashoka from Rebels and Maul vs Obi Wan rematch. TCW various Palpatine episodes. Clone marching scene from AOTC. Maul vs Qui Gon from TPM.
I also like these scenes but the fight between Ashoka and Maul is one of my favourites. Bolba Fett also has some great scenes.