“La Traviata”
Odd, just five minutes ago I was listening to a recording of Siempre Libera: http://www.youtube.com/watch?v=QnKuht1ST-I
And if instrumental music is your thing, there is the haunting and evocative overture: http://www.youtube.com/watch?v=53x5zwEp3cY
La Traviata
The very first opera I ever experienced. At a dress rehearsal.
It was a major learning moment for me, at 11 years of age.