Nikos place has the best view, as you can tell from the pictures, but also I loved that it was quiet and cool at night - unlike Firostefani and Oia, which can get crazy with tourists. Instead you can easily walk to Firostefani and then come back to a quiet place to relax, and truly enjoy the view.
Nikos is very communicative and helpful, as were his porter and cleaner. Highly recommended!