Hawaii is the best vacation place ever!We've been there 4 times now.Flown into Oahu and MAUI.MAUI is the best for renting a car and site seeing on your own.Oahu has the best market for all those shopping times.I know you will enjoy no matter where you go down there.
Here are my reccommendations for places to visit in Hawaii.
Oahu
#1 The Polynesian Cultural Centre (all of the South Pacific Island cultural villages in one place and one of the best Luau's in Hawaii).
#2 Hanauma Bay - Snorkel and swim with tropical Fish
#3 The USS Arizona Memorial - World War 2 History on the bombing of Pearl Harbour
#4 The Quiet Beaches of the North Shore.
#5 Matsumoto Shave Ice in Haleiwa.
#6 Hike to the rim of the Diamond Head extinct volcano crater overlooking Waikiki.
Maui
#1 Drive the road to Hana and visit the pools of Ohe'o (Stay a day or two and take a cave tour).
#2 Watch the sunrise from the Haleakala Crater (and bike down the mountain if you want).
#3 Explore Iao Valley with a stop at the Bailey House Museum.
#4 Walk through the old town of Lahaina.
Kauai
#1 Drive through Hawaii's Grand Canyon - "Waimea Canyon"
#2 Hike along the breathtaking Na Pali Coast.
#3 Kayak the Wailua River to the Fern Grotto or to find a rope swing into the river.
Hawaii
#1 Waipio Valley Wagon Tour or Trail Ride (stay a night or two in a b&b if possible in this amazing valley).
#2 Visit the Volcanoes National Park and tour the crater and walk through lava tube tunnels (bring a flashlight).
#3 Swim in the river at Kolekole Beach Park 13 miles North of Hilo.
#4 Take a boat trip along the canals of the Hilton Waikoloa Village (or watch the dolphins).
Molokai
#1 Ride a mule down the Kalaupapa cliffs to the old Leper Colony.
#2 Visit an ancient Hawaiian heiau (temple).
#3 Listen to Sunday music from the 7 churches along "Church Row".
Lanai
#1 Rest and Relaxation
#2 Explore the Hulopoe Bay Tide Pools and swim in Hulopoe Bay.
#3 Visit Shipwreck Beach to view the lighthouse ruins and the marooned "Liberty Ship" oil tanker from the 1940's.
#4 View the Luahiwa Petroglyphs, drawings carved in stone by ancient Hawaiians.