Maui has the best of everything. Beach, food, sightseeing, activities, etc.
Less crowded than Oahu. I recommend Maui Kaanapali Villas right on the best beach. Great 4 star resort condos you can rent through VRBO.com. Send me a board mail if you are interested in a couple of units my family owns. We could accommodate your group of 10. (Total of three master bedrooms, 3 1/2 baths and two hide a beds in the living rooms.)