I too have found it impossible to cast a vote, as we've loved everywhere we've been, for various reasons. I can't say we've noticed any hike in prices either, and have always been offered freebies like a liquor or a piece of fruit after meals, which we haven't had elsewhere. Admittedly accommodation can be a bit hit and miss, but that's all part of the charm. Only in one resort, have we been hassled by restaurant/bar staff, and to be honest we've had that in many countries that we've visited.
Not possible to choose 1 favourite. The Peloponesse, The Pelion, Lesvos & Tinos are all up there. Even the most touristy places have spectacular features like Rhodes old town, the caldera view on Santorini & the entrance to Symi harbour. For complete variety it has to be Greece for us.