I spend a lot of time in Greece, a few weeks every year for the last 12 years.
Favourite island is Alonissos, one of the Sporades along with Skiathos & Skopelos, all joined up by ferries. Love them all.
Thassos is also very good, that was a new one last year. I drove to the summit of the island in a manky jeep, it was highly risky, edging around boulders on single track mountain roads.
The Mani on the mainland is great, very spaghetti western. Banditry, tower houses, goats and eagles. Patrick Leigh Fermor spent his later days there, in Kardamyli.
I used to have a low opinion of Greek food but its simplicity really grows on you. Same with the wine.
I have just booked our family Greece holiday through https://travelsites.com/last-minute-travel/ . The price was pretty cool so we arranged everything beforehand. Now I'm researching the travel forums to determine things to do and plan thoroughly our time. So keep you posted on what I found out.
Go to Naxos (I think where Orpheus died or something). Stay at a place called maragas. There’s a great nudist beach down the road with a gorgeous rock pool. Watch the sun set behind the island of Paros. Venture up the hills to explore Greek pastoral life. There’s a big, ancient window in the town centre.