one of our favourite spots from a 4 week trip through sulawesi (indonesia) was malenge island in the togeans, more precisely malenge indah cottages on the far side of the island:
there were 5 cottages on a secluded beach, and a maximum of 5 guests total (low season). we were connected to the little village of malenge by means of a 45 minute boat ride, and only now and then saw other humans when a fishing boat passed by in the distance. there was no cellphone reception, and we only had power for a few hours after sunset.
it was incredibly quiet, and the reef was stunning.
what more could you want?