A couple come to mind:
1. Arsenic and Old Lace - a "screwball" comedy about a truly dysfunctional family - starring Cary Grant, Peter Lorre, and Raymond Massey
2. Lust in the Dust - a rather "strange" western with Tab Hunter, Divine, and Laney Kazan. Not for prudes.
3. Young Frankenstein - a Mel Brooks classic with Gene Wilder, Peter Boyle, Marty Feldman, and too many other GREAT comic actors. Possibly one of the best movies Mel Brooks ever made.