Greece can satisfy even the most demanding of its visitors. It has beautiful scenery and great man made establishments, it has sea but also mountains, it has archaeological sites and night clubs as well, it has crowded areas but it also has nice and quite places. The best of all is that all these are not far away from each other. I don't think its an overstatement to say that Greece is a traveler's paradise.
Where can you find such places.
If you want to find fancy restaurants and Hotels and all the comforts a man can get those are the services every known place has and they are actually difficult to miss. Mykonos, Santorini, Rhodes, Corfu, Crete, Athens, Thessaloniki, Samos are among the most visited destinations in Greece. If you need luxurious accommodations, fancy restaurants, loud music, packed cafes, lots of visitors you can find them here.
Places that are not crowded but still have lot to offer are more difficult to find. There are less services and less money to be gained from visitors and therefore are not heavily promoted. If you are looking for those places don't ask at your local travel agent. Don't arrange a Cruise hoping to find them. The are usually very close to the crowded centers but not much is mentioned of them.
Lots of smaller islands that are not heavily advertised, and island satellites to famous ones usually fall under this category and would be ideal places for people that want to explore the alternative Greece. For the sake of the discussion I am going to mention Gaudos, Paxoi, Fournoi, Sifnos, Ikaria, Chios but this is not extensive by any means. These places are usually recommended from people that have already gone there. If you have not had such recommendations then I would advise you to prepare your trip to the most favorable location leaving some room in your schedule for visiting places that the locals will undoubtedly suggest. An inquiry to a local Greek travel agent or a Greek Habitant might reveal some hidden treasures around the area. Keeping in mind the pros and cons presented right after, one can easily recognize such places.
With quiet destinations you avoid the mass tourism and the noise and you enjoy more the nature and the hospitality of people simple and not caught up at the great rush of our times. Nature is purer and the food is fresher and atmosphere is unspoiled and healthier. The prices are cheaper too. One great disadvantage is that such places don't have many means of transportation to and from them and not to many comforts should be expected when looking for accommodation. Some of them don't even have air connectivity with mainland Greece. They might have boat or bus connection 3-7 times a week from the near by Town.
Travel off high season
Greeks usually take their summer vacation around the 15th of August that is the biggest festivity in the Orthodox Christian world, commemorating the Assumption of Theotokos (Mary the mother of Jesus). Around these days everything gets very busy with boats running full and extra flights being added and all types of accommodation running at full capacity. These period makes for some very tiresome vacation and I would definitely avoid it if I had the choice. Planning either before or after August is probably the smartest thing one can do when traveling to Greece. You do avoid the headaches and prices are a whole lot different.
Almost all destinations in Greece are connected through Athens, so this gives an opportunity to the traveler to explore the Athenian lifestyle and Acropolis if he/she so chooses. Some alternative routes include Italy which has daily direct boat connections to the Ionian islands and Turkey which has daily boat connectivity to the nearby islands of the Aegean.
Arranging your car rental before hand
Small places usually luck the public transportation of the big and famous cities. Buses usually run not very frequently and planning your excursions around them usually is not an easy chore. The more crowded places will probably have cars booked fully for the high season times. So if you are planning on using a car arranging it ahead of time is always good choice.
Alternative accommodations for rent
If you are not interested in the standard services of a hotel (food, everyday cleaning/towels/sheets pools and restaurants) you can rent villas or homes at cheaper prices. Usually the such places provide a high level of service compared to what you pay for them. Plenty of non Hotel accommodations are spread at all possible places and the go by the names of "studios" "apartments" "homes" "rooms to let" "homes". Some times its even possible to rent such places a monthly rental fee, provided you will stay for at least 1 1/2 months there.