Lots of bargains available at the end of November and early December. Look at Royal Caribbean's Liberty of the Seas, she sails E and W Caribbean, alternating. Oasis of the Seas is a fantastic new ship, she sails from Fort Lauderdale, E and W Caribbean. Freedom of the Seas sails from Port Canaveral, close to Orlando, E and W Caribbean.
Princess cruises have a lot of bargains, Crown Princess, Ruby Princess from Fort Lauderdale - you can get a week's cruise for around $500 plus taxes.. or 10 days S Caribbean on the Emerald Princess for around $599.
NCL have the brand new ship the Epic sailing 7 nights from Miami, E or W Caribbean. They also have the Pearl and the Dawn sailing various W Caribbean itineraries at bargain rates.
You are spoiled for choice.