Which Greek island is best for culture, scenery and good food?
For some of the reasons Alex described and for many more that the site will not be enough to mention, Kerkyra-Corfu is an island with many different aspects through the ages to offer for those that are willing to search. Only a few more, you will find in the link below. The rest you have to discover on site. However both Crete and Rhodos are also excellent places to visit for the purposes you have in mind. The advantage that Corfu and Rhodos have over Crete is that they are smaller in size and therefore easier to see all they have to offer.