There are lots of choices in Nassau but a lot of people don't seem to like it very much.
When I head there in November to formulate my own opinion, I plan on doing some self touring on my own. That means if it's awful there won't be much of a financial loss. From the looks of the walking tour map I have, everything in the town is in reasonable distance. I'm going to give it a shot and see how it goes.
RCI Sovereign of the Seas 2005
Caribbean Princess 2005
Carnival Paradise 2004