There are two ways of looking at this film: as an opera, or as a movie. As an opera, it isn't that great. This is mainly because of Teresa Stratas screeching and moaning and I'm sure she belches once or twice too. What do you expect from a character whose most dramatic aria occurs in a drunken stupor (he intones with implied sarcasm)? Domingo is good, as is Cornell MacNeill as Germont-Pere. The two men are brilliant singers and not bad at acting either. However, Stratas overacts. A lot. Eh, sopranos.
However, the movie itself is well done. Zeffirelli has an eye for beauty and eye-pleasing scenery. The visual part of the film leaves you with the warm fuzzies, and the actual direction of Domingo really makes you like the character. However, I felt nothing at the death of Violetta. Except maybe a little bit of relief, but let's not let that get around.
All in all, it's a good attempt at cinematizing Verdi's masterpiece, and I agree with some of the other reviewers that it is probably a better buy for opera newcomers.