Not really into opera, but I have good memory of Mozart's Magic Flute filmed by Ingmar Bergman. It's published by Criterion on DVD.
http://www.criterionco.com/asp/release.asp?id=71
Well, this thread intrigued me. I checked the AFI list and discovered that I only have 13 movies to watch to make the 100 (I guess that makes me and old fart ):
All About Eve
Raging Bull (I just bought the DVD though)
The Grapes of Wrath
The Best Years of Our Lives
The Birth of a Nation...