The Boathouse in Wailea/Kihei: your own private studio with lanai, perfect for a couple. Efficient mini kitchen. Pristine bedroom and bathroom, modern decor, very comfortable. Ample supply of necessities (bath and beach towels, toiletries, beach chairs and small cooler too!) you'll feel right at home.
I will come back and stay here when visiting Maui again. Very gracious hosts.