Operatic arias. What’s essential?

I know I need to listen to the whole Opera. We do go once a year, but I'm compiling a CD as a present and wondered what you chaps would include on a list of 10 of the great romantic operatic arias (my challenge was to bring tears to the eyes of the listener without them understanding the words...I said I could, they said I won't!). All my faves are Puccini, but what would be on your list?"