That is a great one! I love It Happened One Night! Young People in Love are seldom Hungry! (Of course anything (almost) with Hepburn and Tracy is also on my list!)
I still laugh when the Colonel calls the cat in Bringing Up Baby. Charlie Ruggles was great. But, yes, Cary Grant usually can make me laugh.
Outside the classics genre, I like Dudley Moore movies and Monty Python.
Another Cary Grant gem: Arsenic and Old Lace.