Crystal is probably the best idea for you. Nothing like Carnival or any of the mass market lines. Excellent food and service, wonderful itineraries, cultivated travelers, no announcements, excellent alternate restaurants, and a crew where the word "no" isn't in their vocabulary.
Unlike Carnival, Crystal is the most formal of all the cruise lines. Most men wear tuxes or dinner jackets, and the ladies wear gowns on formal nights. No going back to the room to change after dinner as Crystal asks you remain dressed in the code of the evening. So, if you don't mind a more formal experience, Crystal is for you.