Great suggestions so far, thanks to everyone for contributing. I've turned this post into a list of everything mentioned in this thread, and will keep adding if more is mentioned.
Frank Sinatra: Days of Wine and Roses
Sara Vaughan: Sings the Mancini Songbook
Lena Horne: Lena in Hollywood
Tony Bennett: The Movie Song Album
Doris Day: Hooray for Hollywood Vol. 1 & 2
Monica Mancini: Monica Mancini & Cinema Paradiso
Fred Astaire: The Astaire Story Vol. 1 & 2
Matt Monro: Invitation to the Movies
Andy Williams: Moon River
Eddie Fisher Sings Academy Award Winning Songs
Mel Torme Sings Fred Astaire
Julie Andrews Selects Her Favorite Disney Songs
Barbra Streisand: The Movie Album
Tony Bennett's "The Movie Song Album" contains a version of "The Shadow Of Your Smile" (from "The Sandpiper") that was specially arranged and conducted for him by the song's cocomposer Johnny Mandel.
I picked up a copy of Sinatra's "Days of Wine and Roses, Moon River and Other Academy Award Winners" at a quirky little music store in Boston a few years back. I love finding little treasures like that. Another reason why we need those cds and those "machines" you play them in.
Here's Victor Young's "Hollywood Rhapsodies" album from 1954.
While most of the album doesn't do much for me, I have to say that the first cut, an arrangement of Newman's THE ROBE love theme, is downright intriguing.