I'd like to see the same actor play Ryan over the course of 15 years or so. The Jack Ryan career story arc is pretty interesting and would benefit from seeing the same actor mature into the different roles as Ryan ages/advances.
I like Chris Pine, too, but I haven't seen any of the Jack Ryan movies, except for The Sum of All Fears, which stars Ben Affleck.
I likes, that was the worst one too. You gotta watch Hunt for Red October, Patriot Games, and Clear and Present Danger. Or just read the books, they're much better.