Star Wars: Alec Guinness
The Empire Strikes Back: Harrison Ford and Carrie Fisher
Return of the Jedi: Mark Hamill
The Force Awakens: Harrison Ford and Daisy Ridley
Rogue One: Ben Mendelsohn
The Last Jedi: Mark Hamill and Adam Driver
Solo: Alden Ehrenreich
I’d add Alan Tudyk for Rogue One, but otherwise this is exactly what I was about to say. As far as the PT goes, Liam Neeson and Ewan McGregor were the only actors who were any good. I guess Christopher Lee gets an asterisk since he did as good a job as anyone could ask for given the fact that he had nothing to work with, but when I think about acting in the PT, Ewan’s really the one who stands out. I suppose Ian McDiarmid was good for a while too, but he’s so god awful after going full Emperor in the back half of ROTS that I hesitate to praise what came before.