Well, I'll probably get shot down here, but one of my favorite films that I believe had breakout performances by both stars was The Owl and the Pussycat, with Barbra Streisand and George Segal.........it was her 1st film where she did zero singing, strictly comedy and some drama, I just never felt it got the attention and award attraction it deserved. Both stars really played their hearts out, just a raw performance from both
Year: 1970
Director: Herb Ross
Writer: Buck Henry
Stars: George Segal, Barbra Streisand,Robert Klein, Roz Kelly, and Marilyn Chambers
Awards: Babs was nominated for a Golden Globe, no win, and Buck Henry for a Writer's Guild award, no win
Trivia bit: Streisand wanted Sidney Poitier as the male lead, but producers or backers thought audiences were not ready for that coupling in this genre of film. Babs was upset, but stayed with the film, she wanted something/anything that was NOT a musical, IMHO, may be her best film choice ever.........