(Although these all say "best" I think mine are really "most favorite" because when I get a favorite, it's the best IMO, even if technically another flick is more superior.)
All-around favorite: Willy Wonka and the Chocolate Factory
Best Sci-fi/Fantasy genre: Logan's Run
Best action movie: The Italian Job (take your pick of versions)
Best romance: Miracle on 34th Street or Victor/Victoria
Best movie that an adult and child can see together: The Emperor's New Groove
Best teen zeitgeist movie: Ferris Beuller's Day Off (I agree with shebit here)
Best all-out comedy: The In-Laws (original, of course!)
Best musical: Sound of Music or Oliver!
Best animated: Kiki's Delivery Service
Best documentary: Walking With Dinosaurs (again, I agree with shebit again)
Best noir/mystery movie: Murder by Death
Best escapist fantasy: Willow (It's got Jean Marsh and Patricia Hayes cat-fighting in it - what more could you ask for?)
Best "bad" movie: The Three Kinds of Heat (Well, it's baaaaaaaaad - and I've seen it a gazillion times. I love inflicting it on my friends.)
Best chick flick: Not my thing, chick flicks... Charlie's Angels has chicks in it...
Best space opera: Star Trek: The Voyage Home (the one least like a space opera... Hmmmmm)
Most Rewatchable Movie: 9 to 5 (if, while flipping through telly, this is on, I watch it until the end)
Add your own genre at the end.
BTW, I showed the original The Italian Job to my seniors today (half were gone due to a band field trip) since I'd showed them the end when we were talking about center of gravity. Some of them seemed to enjoy it. (Alas, we ran out of time just before the big chase scene started - maybe during their study hall someday we'll get it watched.)