Very large domain, needs a specific post with many people interacting because
de gustibus et coloribus non disputandum.
I would recommend to those of you who would like to be initiated to Opera for exemple, to start with Traviata (Verdi). The story of a prostitute, what a coincidence. This is the opera with « hits » from the first to the last note of music. Currently there is a somptuos representation available on YT with Renée Fleming and Villazon (scenography, costumes, this is how you must discover for the first time La Traviata).
But, the most beautiful Traviata is Angela Ghorghiu’s Traviata at the Royal Opera House-Covent Garden in 1994. Angela Gheorghiu is the only
soprano di coloratura in the world who has both the two qualities requierd for Traviata : vocal performance + authentic emotion in the vocal timbre. Unfortunatelly the Covent Garden representation is not available comletely on YT but you can find the DVD or the CD.
When you are in love listen to Angela Gheorghiu’s
Sempre libera (Traviata) or
Je veux vivre (Romeo and Juliet, Charles Gunod), available on YT.
Another representation which could make you love Opera is the Madrid
Barbiere di Seviglia (Rossini) with the handsome Juan Diego Florez, currently one of the three tenors in the world capables to sing all the final notes of the aria
Felicità (watch the min. 2:38:00).
Mozart will be in a second time, but if so, start with his
Nozze di Figaro.
I would advice you to try by all means to attend a real representation, the only way to understand why people become hysterical in a opera house with ‘brava’ and ‘bravo’. And always to discover an opera with a classical scenography, not with all those contemporary attempts which disturb the public. This is a speciality in Geneva, I saw an horrible
Entführung aus dem Serail (Mozart) with a guy masturbating on the stage, or the
Indes Galantes (Rameau) which was a huge orgie with singers in rags.