These days, Celeste Holm's best known movie may be All About Eve (1950), where she supported Bette Davis. Watch:
Well? Did you see her? Did you see Celeste Holm? She was the blond standing to the left of Davis. She said, "We know you. We've seen you like this before. Is it over, or is it just beginning?"
Not to give you the wrong impression, there are plenty of instances in Eve where Holm really does get to show off her thespian skills. She turns in a fine performance in a movie full of fine performances. However, the particular scene that I just showed you happens to be most famous one in the movie (as well as the most available scene on YouTube.) Probably because it contains the most famous line in the movie, uttered by Miss Davis: "Fasten your seatbelts. It's going to be a bumpy night." But Holm set Davis up to say that line! You know, when she said, "We've seen you like this in the beginning. Is it over, or do we know you?" Something like that. Holm supported Davis.
Unfortunately, this equality doesn't last the whole picture. Celeste Holm was, after all, just a supporting actress. One of the best.