During the 1950's, Joan Blondell had a nice late career as a second banana. I loved her trying to keep Jayne Mansfield's Rita Marlowe from going off the rails in "Will Success Spoil Rock Hunter?". And especially her great sympatico comic byplay with Katharine Hepburn in "Desk Set". TCM just showed "The Opposite Sex", in which she probably had the least showy role, but she held her own with some pretty flashy women. She always makes me smile in those roles as women who were past their prime but still had character and the wit to express it.
P.S. "The Opposite Sex" just reminded me of Charlotte Greenwood and what a great second banana she was, especially when paired with someone like Edward Everett Horton (a stellar second banana himself) in those 20th Century-Fox Technicolor musicals.
"When Fortuna spins you downward, go out to a movie and get more out of life."...Ignatious J. Reilly, A Confederacy of Dunces