We did a New Years Eve cruise on the Carnival Liberty a few years ago.
It was quite a party with a very happy crowd. Everyone was up on the Lido Deck and there was music and revelry and plenty of Champagne flowing.
We had a terrific time.
Carnival Liberty New Year's Eve 2007
Liberty of the Seas 5/2008+11/2009
Allure 1/16/ 2011
Independence of the Seas 12/29/2013 Top-notch!