We have been KOA members for the past 5 years. Most are good but there are 1 or 2 we've been to I won't return to. The ones that stand out as great are:
Sugarloaf Key KOA - Especially popular with snowbirds and sites aren't the largest but, it's a clean and fun place. Pricey - $104/night
Hatteras KOA - Very family friendly and like Sugarloaf, right on the Atlantic ocean. Clean, nice size sites and friendly folks.....