Depends on what you want to see.
We did the three hour Nassau historic city tour and it was great..we left right when we docked..it took us to all the famous places, let us out to look around and then brought us back to dock area. This was getting to be lunch time..we asked cab driver for a restaurant recommendation. He suggested Conch Fritters..nice place, great food, relaxing. We spent time at straw market, Senor Frogs, found Hard Rock Cafe, walked up and down the shopping streets a bit, had Lumpia at the philipino restaurant right to the left of the straw market, it was a great day..we had a blast.