Which would you recommend...three days and nights in Santorini or a three-day cruise to several islands including Santorini?
I would spend 3 days in Santorini. On the cruise you won't be given enough time on any of islands plus (for me anyway) sitting on the ship is boring. Santorini is worth the stay. (I've been there twice and to Greece 4 times)
I would stay on Santorini, make sure to take the trip to the volcano, wear comfortable shoes, no sandles and Take a bottle or water. Try to say as high up in Santorini as possible. The view is wonderful
Santorini would be my choice. We got our cruise needs out on a beautiful ship from Crete to Athens. It was a night trip.