Favorite But Underrated Movies

Network, but it isn't underrated.
Just watched Frantic, Roman Polanski film with Harrison Ford. It was really good.
If you can find a good copy, Cary Grant's "His Girl Friday"
While sticking with the oldies, Arsenic and Old Lace, It happened one night, Easter Parade, Holiday Inn, Donovan's Reef, and Harvey are all good too.