FAVORITE OPERA? I find this question impossible to answer because there are so, so many great works. I'll give you a few:
Salome (Richard Strauss, beautiful poetry of the libretto by Oscar Wilde, incredible music, extremely difficult soprano role)
Don Giovanni (Mozart, stunning music, great ensembles, cool story)
Rigoletto (Verdi, gorgeous music, compact, interesting story, incredible last act)
Il Trovatore (contains, IMO, Verdi's best ensembles)
La Traviata (Verdi at his best, the whole opera is in waltz time, gorgeous arias
I have three CDs entitled .Opera Without Words' which of course is just the great tunes played by a symphony orchestra without the singing. They are performed by the Rome Symphony Orchestra conducted by Domenico Savina. The three are the Giacoima Antonia PUCCINI's Madam Butterfly/La Boheme and Tosca.
My favorite is what I am seeing or what I am singing at the time. Traviata (I lived with Violetta.) Verdi; Fiordilligi In Cosi fan Tutti - Mozart; Manon - Massenet.; - Liu - Turandot; Sonia - Merry Widow - Lehar - etc. Favorite operas?- TURANDOT & LA BOHEME - Puccini.
I once conducted a youth orchestra and three talented teenage singers in the Trio from Rosenkavalier. That was spectacular.
I heard a story from a friend of one of Richard Strauss' assistants. One evening Strauss suddenly got up from the dinner table without speaking - went into his study and didn't come out for several days. When he emerged one of his operas was written. It could have been "Salome." Strauss was criticized for cooperating with the Nazi's. He was German and there during those awful years. This same person told me how angry and sad he was when Jewish
performers were taken away by the Nazi's. He was prominent and therefore with some influence which he used to protect his Jewish daughter-in-law and his Jewish grandchildren. He could not protect this daughter's grandmother and her other children who were killed in a concentration camp. He was far from a Nazi sympathizer.
I can't decide but its a close call between Rocky Horror and Repo.
I'm a classically trained "metal head" and didn't develop an appreciation for classical music till college...which generally didn't include period opera.
I'll make an exception for Wagner, especially Der Ring des Nibelungen. That rocks.