I’ve done two trips to Maui (Sept and Nov) and have spent the most time there. I recommend staying near Kāʻanapali (kahn-ah-paul-lee) on the West Side of the island.
(Red circle is Kāʻanapali, Blue circle is the Airport). Kāʻanapali is about an hour from the airport. Traffic flow is a bit slower on Maui than on the mainland… people aren’t in a rush. The road takes you along the ocean and has amazing views - enjoy it!
There are two spectacular beaches on the West Side of Maui. Kapalua Bay Beach has a really surprising entrance and free parking is available early in the day (8 AM). This is a gorgeous beach with good snorkeling and is very relaxing.
Black Rock Beach is by The Sheraton. Free parking is limited in the parking garage (6ish spaces) - you have to get there early (8 AM). At this beach you can often swim with turtles. People jump off the rocks at the right side of the beach, which is pretty entertaining to watch… kids climbing up there, then having to work up the nerve to jump from 15 feet after they’ve been up there for a few mins. You can snorkel out near the rocks and watch jumpers splash into the ocean too.
The West Side of Maui faces Moloka’i and Lanai. Being on an island in the middle of The Pacific facing an open ocean can become semi-boring visually after a few days. Having islands in the distance adds something visually. Even though you know you’re on an island, seeing an island from an island seems to make the scenery more interesting.
Maui has a very charming town on the West Side near Kāʻanapali named Lahaina - you can shop, eat, and just enjoy walking around town. North of Kāʻanapali is a Ritz Carlton resort with a Burger Shack that has spectacular views and good food/ice cream. Prices are not going to be reasonable, but the view is worth the price. Farther north is the Nakalele Blowhole, which is neat to see. South of Lahaina is shopping at Whalers Village (just south of Black Rock Beach).
The south side of Maui has a spectacular beach named Wailea Beach. This is 40ish minutes from Kāʻanapali.
Wailea Beach is the stuff dreams are made of - when you dream of a tropical Hawaiian paradise, this is the beach you dream of.
Near Wailea Beach is luxury shopping at The Shops at Wailea. This is an interesting mall to visit and perhaps a good place to grab a bite of food.
You may hear chatter about The Road to Hana (which is on the east side of the island). I haven’t done The Road to Hana as it essentially takes all day (3 hours each way at 30 mph). I went to Twin Falls (first waterfall on The Road to Hana), saw the bamboo trees, and then turned back. I'm not convinced I missed anything. It seems like most of the reachable waterfalls on The Road to Hana probably look similar.
Doing a helicopter tour flys over many waterfalls, some near Hana, and that's pretty spectacular.
The helicopter tour flew over Haleakalā (hal-e-ak-ah-la) which looks like something out of a movie, I presume Mars looks like this.
I was scared of flying in a helicopter, and as the pilot was taking off, I had second thoughts and sort-of asked him to land so I could get out. Fortunately for me, the pilot dismissed my request as he continued taking off and told me how great of a day it was for the tour (he played some relaxing music which helped calm me down). I’m glad I went, because it was amazing!
Doing sunrise at Haleakalā is a tremendous experience also, if you're in Maui for more than a week. This means booking tickets a few days ahead, then getting up at 3 AM and driving 2 hours to be there for sunrise. It’s cold (40ish degrees at 10,000 feet), and semi-wears you out for the day - however, it’s memorable and worth doing, again, if you’re in Maui for more than just a couple days.
Ho'okipa Beach Park, North-East of the airport, always seems to have turtles sunbathing and kite surfers tearing up the waves at sea. Very chill!
Lastly, if you have ample time while visiting Maui you can take a ferry to the island of Lanai for the day. Lanai’s very laid back, has an amazing Four Seasons Hotel, and has one of the best snorkeling beaches in the US, perhaps the world. On our ferry ride back to Maui we saw spinner dolphins. The ferry ride may be a good alternative to a boat tour as you may get more bang for your buck!
Bonus: Maui videos
Hawaii Vacation Guide - Maui Snorkeling
Ryan Shirley's 10 places to visit in Maui
Maui | The Big Island | O'ahu | Kauai | Lanai