Bunaken is an island of 8 km², part of the Bunaken National Marine Park. The Island is located at the northern tip of the island of Sulawesi, Indonesia. (wikipedia)
It is claimed that this park has seven times more genera of coral than Hawaii, and more than 70% of all the known fish species of the Indo-Western Pacific. (wikipedia)
I didn't went scuba diving, but when I went snorkeling I saw many beautiful fishes.