Check out Kauai.
We did a 2 week honeymoon there. Loved it. I can even refer you to a wonderfully inexpensive, but flat out fantastic bed and breakfast that will include practically any ammenity you could think of. Except obviously you'd have to take care of dinner and lunch. Kauai isn't terribly hot, and the sun comes in spurts, so it can be a gentle overcast and cool breeze one day, and warm and sunny the next.
Plenty of places to explore. Tons of hole in the wall places to eat that are fantastic, though not upscale, but definitely qualify as adventurous. Hardly at all touristy, and the locals are incredibly polite.
There are a number of activities on the island if you're into that sort of thing, but mostly just get out and about and see the scenery.
Feel free to PM me, I can give you any info you'd like about Kauai.
