Let KAYAK do the searching
Based on KAYAK hotel searches, the most popular destination is Athens (87% of total searches to Mainland Greece). The next most popular destinations are Thessaloniki (7%) and Piraeus (3%). Searches for hotels in Nikiana (3%) are also popular.
KAYAK users have found double rooms in Mainland Greece for as cheap as $18 (Athens) in the last 3 days. The average price is $280.