Billy Wilder's "The Apartment" was nominated for 10 Oscars, It won 5, including Best Picture. I think it could do so again today.
Jack Lemmon gives a fantastic performance as C.C. "Buddy" Baxter, a put-upon bachelor who is caught up in a never-ending cycle of loaning out his apartment to executives in his company, so that they can cheat on their wives.
Baxter appreciates the popularity until he takes a shine to Fran Kubelik (Shirley MacLaine) an elevator operator at Baxter's company.
Oh, and if you've ever wanted to see an actor cast against type, Fred MacMurry's (The Shaggy Dog, The Absent-minded Professor, My Three Sons) performance as Jeff Sheldrake is a real piece of work.