Restaurants & Cafes
Lahaina Grill
Fancy, more expensive, but great food and ambience
Also worth trying (others' recs)
Sightseeing & Activities
Haleakalā National Park
Ho'okipa Beach Park
Saw lots of turtles here (may depend on season or time of day)
Honolua Bay
Great for snorkeling
Road to Hana
Wai'ānapanapa State Park
Check if you need a permit before going
Also worth trying (others' recs)
On my list for next time