I don't usually recommend Luaus as they tend to be awful food and kitchy entertainment...but I echo what has been said about Old Lahaina Luau, I was very impressed with the food and excellent entertainment, probably the best in all the islands. The owners of Old Lahaina Luau also have another "experience" in Lahaina called "The Feast at LeLe" which I haven't done but have heard great things about.

David Pauls is a don't miss restaurant in Lahaina (make reservations).A Pacific Cafe is excellent in Kihei. My new favorite restaurant in Wailea is Tommy Bahamas(in the new Shops at Wailea), they prepare food well and the service levels are higher than most Maui restaurants.

I also like the Aquarium at Maalea Harbor, it's not the Monterey Aquarium by any stretch of the imagination, but interesting (and alot better than the aquarium at Waikiki).