The film stars Gloria Swanson as faded silent film star Norma Desmond, William Holden as the down on his luck screen writer as Joe Callis, Erich Von Stroheim as the butler Max, Cecil B. DeMille as himself, and Nancy Olsen, as the young script reader who falls for Holden, although engaged to his pal, Jack Webb. Buster Keaton and Hedda Hopper also have small roles in the film. 
There are many memorable lines in the film, most notably "Without me, there wouldn't be any Paramount studio" and of course, "I'm ready for my close up".  Beside Swanson, the real star is the film itself with its witty script and near film noir like quality as it takes aim at life in Hollywood and the film industry in general. 
This new edition features a pristine print ; I couldn't find a speck of dirt or flaws of any kind.  The picture was sharp and clear throughout.  Sound is equally impressive in Dolby digital mono.

Disc one has commentary from Ed Sikov, who authored "On Sunset Boulevard: The Life and Times Of Billy Wilder" and is filled with great information about the film and director.
Disc 2 is loaded with special featurettes from all aspects of the film: The Noir Side of Sunset Boulevard by Joseph Wambaugh, A Potrait of William Holden, Two Sides of Gloria Swanson, the famous Morgue Prologue script pages, a Hollywood location map and Behind The Gates: The Lot.  It is a fascinating look at the film and era of Hollywood of the 50s.

"Sunset Boulevard: The Centennial Collection" is a great disc set and classic film fans are in for a treat with this new edition with flawless picture, sound and a ton of interesting extras.  Highly recommended.