Caesar, written for castrato, is often sung by a countertenor.
An epic of love and war often considered Handel's finest work, Giulio Cesare has a richly intricate plot and the bonus of a brilliantly characterised and outrageously seductive Cleopatra (see Glyndebourne's Opus Arte DVD with the dancing Danielle de Niese as Cleo). Caesar, written for castrato, is often sung by a countertenor. Other good Handel: Rinaldo, Radamisto, Tamerlano, Rodelinda, Ariodante, Alcina.