Stayed for 2 weeks. Direct Delta flight from JFK to Athens. Stayed 2 night in Athens to see the Parthenon and local sites. Took a ferry to Naxos, the largest of the Cyclades islands. They have very nice beaches and not as commercialized as some of the other islands. More geared to a family (I have 11 year old twins) than Mykonos or other "party" islands. Stayed for 6 nights in Naxos (rented a car because it's a big island.) in a villa in the hills with a nice view of the port town Hora. Then took another ferry to Santorini for 4 days. Then flew back to Athens and flew back home the next morning.
An excellent trip!