Greece Itinerary

How about we narrow this down at little with some questions:
Are you planning to go this summer?
Do you want to do mainland ( Peloponnese), islands or both?
Are you interested in history or beaches and relaxing?
How many days are you planning to spend?
Are you planning to drive or use other methods of transportation?

Once those questions are answered, then posters can begin to make suggestions. You could also check with your local library for guidebooks or check the itinerary that the Rick Steves' Greece tour follows.

Make sure to be aware of the temperatures in Greece in the summer - I was there last year but went in the spring to avoid the HOT weather in the summer.

If you are looking for value, then avoid Santorini and Mykanos at all costs. In my opinion Santorini is far too overrated and too full of tourists these days.

Better value are islands such as Corfu, Lefkas, Paxos, Skiathos and Crete. The Ionian Islands have a bit of a breeze which is needed in the summer. If you want something quiet, Alonnysos is great and not as overrun with tourists, although being the summer, everywhere with have some tourists.

Nafplio... one of the most charming places I have visited.... just beautiful.