What island did you stay on?
Maui. We loved Maui--friendly, relaxed, quiet, stunning scenery. So many different "types" of land in such small space--desert looking areas, rainforests, mountains, beaches, farms/plantations... just so incredibly beautiful. The island is small and easy to get around. It's quiet. It's just... incredible. I could feel the stress melt off my body the moment we stepped of the airplane, I can't even explain it.
I suppose if you want lots of nighttime entertaintment (dancing, clubs) then it's not the best pick of an island, but honestly I can't imagine even going anywhere else now. Our best friends just got back recently from their honeymoon, too... they stayed at Oahu and Maui (split) and also said they liked Maui best.
What hotel/resort?
Four Seasons Resort Wailea. I can't say enough good about this resort. We are NOT rich by any means, we made it work by booking the cheapest room category and using a special that the hotel was running at the time. Incredible service--complimentary champagne and roses in our room one night for our honeymoon--stunning landscaping and interiors--friendly staff--good food--heck they bring you towels and spritz you with water while you're lying on the beach--just absolutely amazing. We didn't have kids obviously, but there is a Kids Program for them. The pool was GORGEOUS.
Now all this said... if and when we go back, I probably will not book the Four Seasons again--ONLY because of the cost, though, and ONLY because there are other beautiful, quality resorts for less $$. That was a once-in-a-lifetime splurge for us (honeymoon trip). I'd still probably pay to spend money in the Wailea area though--that part of the island is just incredible--sheltered from the wind, never got a drop of rain, stunning views, etc.
Things to do?
What we did: spent a day in Lahaina shopping and seeing the sights (loved it), helicopter tour of the island (loved it), beach (both at our resort and at Little Beach--nude beach!

--loved it, but obviously not for everyone), luau, shopping at the Wailea mall, and a Molokini snorkel/snuba cruise (very cool--snorkeling and snuba'ing off of Molokini crater and then a second snorkeling stop at "Turtle Town"--area where there's lots of sea turtles).
We didn't do any hiking (totally regret this--meant to but I got sick and just needed a rest day) and didn't get up to Haleakala (again big regret), but you can do that too.
Restaurants?
Oh man, can't remember... good food though!
We did a luau one night at a neighboring resort. Will have to see if I can figure out the places we ate...
Edited: okay one place we ate was Cheeseburger in Paradise. Also Humuhumu's. (Figured this out from reading the other posts, lol!). And I agree with the PP on both those--good food, nice setting for Humu's. We also ate at an Italian restuarant somewhere though (LOL, yes in Maui) that looked like a hole in the wall (and sort of was) but had FANTASTIC Italian food--the real deal. Can't remember... augh....
What time of year did you go?
First week of November, 2002. (PERFECT weather--80 degrees and sunny, absolutely no rain, not a drop of humidity)
Oh oh oh... we used a
travel agent for booking the flight and room. Hawaii 5-0. They got us airfare from the eastern U.S. for much cheaper than I was able to find on my own.