Planning a trip to Hawaii. Tips from locals?

[Royal]

Aloha,

My 5th wedding anniversary is coming up next spring. I want to do something pretty big. I joke about going to Hawaii or somewhere tropical. Traveling is a pretty hard for us (finances, obligations, orchids). But I know that I could afford to surprise my wife with a trip - if I had some travel tips from locals or travel-wise members. We've never been, so I don't know where to start.

We are not huge tourists. We don't need to swim with dolphins or para-sail. We'd rather steer clear of the big crowds and stay somewhere a bit secluded. We'd probably snorkel, take in the beauty, just relax. I'd love to see some natural areas and experience the culture - but I don't want to spend tons of money on large guided tours with a bunch of Texans.

Any ideas or tips to help plan a cheap, but nice trip for a young couple? Thanks in advance!