The General Store near Makawao. Don't let the "general store" title throw it off. It's one of the best on Maui! It's like "maui formal" so it's not really that dressy, but it's very nice. We saw Alice Cooper there once!
A big ditto on Mama's Fish House. We also really liked Humu... at the Grand Wailea. I wore a nice sundress and flat sandals to both and felt appropriately dressed.