If you're looking to experience the Bahamas culture, then I would recommend one of the itineraries that stops in Nassau for your next cruise. Specifically, I did the 4 night Majesty of the Seas cruise a couple years ago and loved it.
2007 - Majesty of the Seas (Bahamas)
2009 - Enchantment of the Seas (Western Caribbean)
2010 - Freedom of the Seas (Western Caribbean)
2013 - Golden Princess (Alaska, roundtrip from Seattle)