In the course of writing Bel Canto, I had the chance to listen to a lot of opera. Here are my favorites (in no particular order):

• Mussorgsky's Boris Godunov
• Handel's Partenope (and a dozen other Handel operas)
• Tchaikovsky's Eugene Onegin
• Verdi's Don Carlos (and a dozen other Verdi operas)
• Bellini's La Sonnambula (I can't explain this choice)
• Offenbach's Les Contes D'Hoffmann
• Puccini (I wouldn't know how to pick)
• I'm also a huge fan of aria collections, especially the Callas La Divina series.