Hi Debs,
Have stayed at many beach resorts but unfortunatley not for a long time.
Naples is definitely the nicest place we have been to, quiet and refined but not a lot going on and 3 or 4 days would be enough.
We stayed at the Registry Resort hotel (not known by that name anymore) on our first visit and 'a Quality Inn' on our other stay there.
Beach is secluded and not too 'touristy'.
Clearwater overall is our favourite beach, though at present there is a lot of work going on there both on the beach itself - they are building what they call a 'Beach Walk' - and construction work with new hotels etc, north of Pier 60 (the main landmark) is quieter and parking easier.
It's also more popular with younger people and more crowded than the likes of Naples and Sarasota.
We have also stayed on the Atlantic coast at Boca Raton, Miami and Fort Lauderdale where there is a great hotel called Pelican Bay.
Much more to do down here for nightlife, shopping and places 'to be seen'.
The 2 nicest actual beaches I have been to are Siesta Key just outside Sarasota and Anna Maria Island near Bradenton are possibly THE nicest beaches in Florida but....as with Naples very quiet, not necessarily a bad thing?
This website is very good and he agrees with my choices!
http://www.beachhunter.net/index.html
I suppose ultimatley it's down to whether you want the best beach and a quiet relaxing week, or a nice beach but plenty going on.
If it's the former then Siesta Key, Anna Maria and Naples are ideal, the latter then probably Fort Lauderdale, Miami and Palm Beach area perhaps?