This is, admittedly, profoundly dumb, but I would've been at least a little interested to hear him continue with a stream-of-consciousness list of movies that should've instead won Best Picture (putting aside the obvious problem that movies from 1939 or 1950 can't be named the Best Picture of 2019): Gone with the Wind...Sunset Boulevard: the former might be demographic pandering, but the latter is an interesting off-the-top-of-his-head pick; what comes next, I wonder? We already know he loves Citizen Kane.
My guesses for what else would've qualified for the Trump Hollywood Classics Canon had he continued naming movies: High Noon, Butch Cassidy and the Sundance Kid, Lawrence of Arabia and/or Dr. Zhivago, The Alamo and/or The Green Berets, The Great Escape, It's a Wonderful Life, Mr. Smith Goes to Washington, The Ten Commandments, North by Northwest (I feel like this would be his favourite Hitchcock, or at least the first one that would come to mind***), and, if anything since 1980, Unforgiven, A Christmas Story, The Passion of the Christ (demo pandering pick), The Shawshank Redemption, Saving Private Ryan.
***Edit/reconsideration: His actual favourite Hitchcock movie is probably Vertigo (though he might still reflexively claim the safer NbNw), as it seems like there's a very high-percentage chance that he finds it intensely relatable in the same way he apparently does Kane. BUT does he relate more to the Jimmy Stewart protagonist or to the rich guy who hires him to spy on his wife? Inquiring minds want to know!
