As cliche as it sounds, one of my favorite vacation spots to go to are the Hawaiian islands.
I've been to Oahu, Maui, Hawaii and Lanai. The only ones left are Molokai and Kauai. I'll get to them someday
So here's my take on the islands I've been to.
Oahu. This is the main island most people go to for their first visit. Out of all the islands (and I know I'm gonna ruffle some feathers) it is my least favorite. It's just too crowded for me personally. Waikiki isn't all that it's cracked up to be. It kinda reminds me of the Vegas Strip with all the hotels lined up one after another (minus the gambling of course). I dunno, it just didn't do much for me.
The Arizona Memorial is touching, and being there, I could just imagine the Japanese dive bombers flying overhead dropping their loads, explosions everywhere. I do like the Dole Plantation, if not for anything else but to have what is basically Dole Whip. I mean hello, Dole Whip IN Hawaii!!
Maui. I do enjoy Maui. It's really changed though since the first time I was there in 1989. Many more people have discovered this island since then.
A trip up Haleakala is a must, but the best time to go is early in the morning, as the trade winds usually bring clouds in the afternoon, obscuring the views of the crater. And bring a jacket if you have one, it gets REALLY chilly up there! The sugar Cane Train in Lahaina is a fun thing to do. Scuba diving on the west side of the island is awesome as well!
The trip to Hana though, not really worth it. It takes so long to get there on a really curvy road that by the time you arrive and maybe have lunch, you have to turn around and head back. There's just not much to do. I suggest taking the road maybe for 20 minutes and pull into this preserve area (can't recall it's name but you can't miss it, you drive right through it) and walk around. It's all rainforesty and stuff.
Hawaii. My absolute favorite island (so far). There's just so much to do here.
A trip to Volcano Nat'l Park is a must. It's a good day trip, but it's worth it. And while on the way you can head over to the southernmost point in the United States! Plus there's the Volcano Winery nearby. I didn't care too much for the wine, but wineries in and of themselves are cool to visit.
Check out Hawi at the northern part of the island. It's where King Kamehameha was born! Cute little village to walk around and have a meal at.
Might I suggest a sunset dinner cruise out of Kona. I had such a great time when I did this. All you can drink mai tais, dinner, and a show.
Lanai. This has to be one of the most relaxing places to go. There's only 3 hotels on the island, 2 big resorts and one small hotel in the middle of Lanai City. I stayed at the latter and it's a quaint little hotel full of old Hawaii charm with a world renowned restaurant. There's a shuttle that takes you from one resort (on the southern part of the island on the beach) to the other (in the middle of the island NOT on the beach).
Rent a Jeep and drive around the mostly dirt roads! It's a blast. See Shipwreck Beach. Drive through Garden of the Gods. Take the Munro Train up the mountain. See the petroglyphs. It's really a fun island!