My personal fav of the three is probably The Apartment, they're all great though. I still want to see Wilders The Lost Weekend and Double Indemnity.
Since you didn't mention it, in the previous three, i did not mention it. DI and Sunset Blvd would tied for #1 for me, then the Apartment, then Some like it Hot. I haven't watched Lost weekend, the plot did not excite me somehow!