Krabi in Ao Nang area is too crowded and too commercialized but if you stay in Rayavadee or Tubkhaak area will be very nice. If possible, go out and stay on the Lunta Island. Pimalai on Lunta island is very beautiful.

There are so many beautiful and quite hotel in Samui. Bann Taling Ngam is very old and will renovate their room next year. Boat house is too crowded. Tong Sai Bay, Renaissance, Evason Hideaway are worth trial.

Good luck. ^