We have done most of our cruises the first week of May. This is before schools let out, not near a holiday and the prices have not gone up for the summer. Our next one we are looking at is end of Sept or Oct. These prices seem a bit cheaper than May (not much) but it is during hurricane season in the Carribbean.
Best advise... pick a cruise line then compare itinerairies of when and where you might want to go, along with where you want to leave from. Good luck.
Sensation (without KathieLee) July 2001
Paradise (smokefree) March 2002
Valor (inaugural season) May 2005
Truimph May 2007
Fascination (1st time w/DD) May 2008
Pride (with DD & DS) November 2009