I enjoyed the Kennedy Space Centre, but this is probably not everyones cup of tea. Or the Everglades if you are an outdoors / nature person. Never done a cruise but this would be probably the cheapest place in the world to grab one, assuming you don't mind being stuck with a couple of thousand American tourists that is!
I have never explored the south or west coast areas much (heard Tampa area is nice + claimed most electrical storms on earth if you enjoy them like I do!), but the north & the panhandle in particular are not so exciting if you are looking for touristy stuff, some nice beaches if you want to sit back and do nothing much though. Be careful during school holidays, some parts get flooded with crazy kids. Visited Daytona Beach once, looked around for 2 or 3 hours and hated it so much we drove off & got a hotel elswhere. Overcrowded, overpriced, overdeveloped and mostly dirty + lots of idiots about; QLD Gold Coast is far better.