I recommend staying near Plaka as this is the major tourist hub of the city and close to the Acropolis.
Crete is a beautiful island that has much to offer. It is a large island with many must-see places such as the cute town of Chania, Knossos which is the home of the Minotaur and is near the town of Heraklion, and the relaxing seaside town of Elounda!
Santorini, or Thera, is home to the best sunsets in the world and home of the Minoans over 4,000 years ago! There is amazing history on this island, and the famous Fira to Oia hike.
Corfu is known for it's beauty and partying scene! Definitely a bustling island during the peak season, but always worth it for the sights!
Another island known for parties, Mykonos has lots of clubs and bars to explore if this night life is your style! Lots to do on Mykonos and fun to explore!
Naxos is one of the few islands in Greece that does not get cruise ships. It is a much more relaxing vibe, and is small enough to get around easily when exploring.
Nestled right next to Naxos, Paros has a similar vibe. Great for relaxing and exploring!
Milos has amazing beaches and is less popular than Santorini and Mykonos. Though, it is more limited of an island so this is a destination if your primary goal is to relax!