Completism aside, why should you shell out for these Chaplin discs when all four titles have been previously released on decent-looking DVDs? Quite simply, because they're gorgeous.
Working with print and sound elements from the Chaplin estate (six more features and seven shorts will be released next year), the French company MK2 has digitally restored the films, coaxing out a wonderful clarity and ringingly rich black and white. ''The Gold Rush'' is still Chaplin's most perfectly realized comedy and one of those rare movies that enchant anew no matter how many times you've seen it. Viewing advice: Go with the restored silent version on the bonus disc instead of the 1942 rerelease for which Chaplin replaced intertitles with an annoyingly wordy narration.
''Modern Times,'' which plays like ''Metropolis''' antic twin, is another delight with its abundance of famously hilarious set pieces -- Charlie trapped in the cogwheels, his freak-out ballet, his gibberish song-and-dance number, and much more. (A nifty demo on the ''Modern'' bonus disc illustrates how Chaplin controlled the pace of the gags and performances by manipulating the camera speed.) Despite brilliant interludes, ''The Great Dictator'''s ambitious mix of slapstick and earnestness doesn't stand up. However, a terrific making-of doc makes the case that Chaplin was the first prominent filmmaker to tackle Nazi brutality and anti-Semitism (against studio wishes, initially).
If the ''Limelight'' discs are the weakest, it's because the film, about a burned-out vaudevillian and the young ballerina (Claire Bloom) he loves, is overburdened by Chaplin's creaky script and fussy acting. Nevertheless, his musical duet with Buster Keaton is an absolute gas, proof that even when Chaplin was bad, he could still be good. ''The Gold Rush'': A; ''Modern Times'': A; ''The Great Dictator'': B; Limelight: B-