Garbo is just remarkable here. Her silent era training is evident as she uses her face, her eyes and her body - rather than her voice, to show us Marguerite's physical deterioration. She LOOKS sick - beautiful, but quite ill. Yet she is not overstated or exaggerated. She is the epitome of suffering, trying to summon her last ounce of strength to greet the man she chased away.
Also wonderful is Lionel Barrymore as Armand's father, Monsieur Duval. Barrymore could play his character as a villain, but he does not. Monsieur Duval is merely a loving father who dreads hurting a woman who seems to be very sweet, and very much in love with his son, but who will soon cause his downfall if they continue their relationship. When one realizes that Barrymore is less than 2 years from being forced into a wheelchair for the rest of his life (he suffered from severe arthritis that prevented him from walking), one realizes that he is acting through his pain.
Robert Taylor, too, is excellent, with Armand's naivety shining from his youthful face. Armand seems sometimes like a sex object - a lovely creature for Marguerite to adore. Taylor fits that bill as well, but also is able to make you understand why Marguerite would give up everything to be with this lovely, gentle man.
This is a beautifully designed film as well, with magnificent costumes (by Adrian). Our group had a bit of discussion on the tendency of some films to not quite get the hair style right for the period - which is NOT the case here. The whole atmosphere of the film is perfection. It is interesting to note that the silent version of the film is also available (on the DVD of Camille), with Rudolph Valentino as Armand and Nazimova as Marguerite. It is certainly worth a look if only as a comparison to its magnificent remake.
Here is a trailer to the Garbo version: