We did our own thing in Crete. We took the shuttle bus from the port to the town. It is a beautiful place with nice shopping and a great water side area to have drinks and/or lunch. It is a nice port for a relaxing day.
We didn't really like Athens. We walked into the centre and took a bus tour in the city. It is a huge bustling city. To me it was like any other big busy city. If you want to see all the historic sites then go on a ship excursion. The feedback from fellow guests was very good. If you have no interest in seeing historic places then stay on the ship and take advantages of reduced spa packages and a quiet pool deck.
We tried to get the tram but had no change for the machine. After passing the most pushy taxi drivers in the world we took the celebrity shuttle bus into town. Although it was $15 each it was worth it. The grand bazaar is crazy. Do not be intimidated by it. Once you get used to it it is a fascinating place. The blue mosque is amazing.
We went to a Turkish dinner show in the evening. It was really good and entertaining.