Although my impression of Honolulu is limited, it is LA South with all the the hubbub you'd expect in LA. However there are museums I really want to visit.
I'm a Big Island person. We plan on retiring on Hawai'i, Hilo area (East side) in about 4 years. We're going over for 3 weeks the end of June early July, and will stay in a friend's condo on Hilo Bay.
If you are interested in geology and hawaiian history, Hawaii is excellent. If you enjoy driving vacations, Hawaii is excellent. From Kailua, Kona, to Hilo is 100 miles around the N end or 100 miles around the S end. In our first visit, we rented a brand new Mustang that had 34 miles on it when Kevan drove off the rental lot. We returned it 7 days later with 1255 miles on it!
Since it is the newest of the islands, the beaches have not had the chance to develop as long as on other islands. The N end (Kohala) last erupted 60,000 years ago. M.Kea last erupted 5,000 years ago and is considered at least dormant, if not dead. M. Loa erupted in 1984. And, of course Kilauea is erupting - pouring lava - as we speak, adding new land to the island.
There are a couple of small but good museums in Hilo (2nd largest city in the state, 45,000 residence). the Tsunami Museum and the Lyman House. In the SE you have Volcanos Nat'l Park which inlcudes Kilauea - Madame Pele's home, of which the vent Pu'u O'o has been erupting now for 22 years. Night visits you can see the red lava flow.
The W side is most touristed, with Kailua Kona being the center. There are many archeological sites to visit, including Kamehameha the Great's Heiau, or temple site, from where he began his conquering of the other islands, all except the lewards - Kauai, and its couple of tiny nearby islands. (Later conquered by Liholiho, King Kamehameha II.) There's the City of Refuge. A truly holy place. And the coffee plantations. King sugar is now gone from Hawaii, but I think there is a small mill operating on Maui.
Then you have the tallest mountain on earth: Mauna Kea (White Mountain) which from it's base in the oceean is 33,000 high. 13,900 above sea level. It and Mauna Loa (Long Mountain) get snow in the winter, while it's still in the 80's at sealevel.
I want to do a week on Oahu sometime. Kev is a WWII history buff and we want to do all the museums there, and the Polynesian Cultural Center (supported by the Mormons). Kev has sailed to/from Hawaii several times, landing at Honolulu, and Kaneoe (N of Honolulu), and Hilo. He's also vacationed on all of the islands, but that was 30+ years ago....
No matter what Island you choose, GO! You won't regret it. It is truly a sacred place and Paradise on Earth. Enjoy a fresh Papaya with limejuice for me.
PS Read Michner's Hawaii for some basic history before you go. It's "novelized" and many characters and locations have been combined, but the story line is generally true to history.