Can definitely recommend the Tropicana Restaurant, food very good and reasonably priced.
You get really nice cocktails at both Kelfos and Sunshine and they are placed well for people watching.
I didn't go on the sunset cruise myself but I heard from others that it was very good, and romantic!
The beach bar in Hanioti has lights over the water in the evening and you can actually stand in the water with your drink, with the little fish swimming all around your feet.
I would definitely visit Polychrono, Pefkohori and Afitos if you have a car.