My wife and I are trying to decide on a cruise for early this December. We sailed the Carnival Glory a couple years ago, and enjoyed it.
We plan on getting a balcony, and may have some friends joining us in an inside stateroom. We want interesting ports, good food, and a ship with a lot to do for people in their 20's-30's. We also want to cruise with fewer children around, but I suspect that will be the case in early December as most kids are still in school.
After looking at the reviews on this site, we've narrowed it down to these 6:
Holland America Zuiderdam (Grand Turk, Tortola, St. Thomas, Half Moon Cay)
Norweigan Sun (Roatan, Belize City, Costa Maya, Great Stirrup Cay)
Norweigan Dawn (Cayo Lavantado, Tortola, St. Thomas, Great Stirrup Cay)
Carnival Triumph (Half Moon Cay, St. Thomas, San Juan, Grand Turk)
Carnival Valor (Nassau, St. Thomas, St. Martin)
Carnival Freedom (San Juan, St. Thomas, St. Martin)