Puerto Rico is great for kids. The old city is very interesting, forts to visit, narrow winding streets, etc. The rain forest should interest them. The beaches, with the parasailing, banana boating, jet skiing. My kids 16 and 14 LOVED it as much as Hawaii, and it was so much closer (and less expensive)

I also vote for Yellowstone, Jacksonhole, Grand Tetons. Loved it. We rented a condo there. Got a three bedroom, two bath, beautiful condo for 5 nights at $200 a nite and drove to all of the sites. Loved Jacksonhole for shopping and eating. Loved Grand Teton National Park and Yellowstone as someone else has said, is like visiting another planet. It is God's country, by far.

something that was beautiful and fun, and outdoorsy wihtout all the work was a trip with SeaQuest to the Baja to watch the whales. They supply tents, Kayaks, and food and guides, you bring a sleeping back and snorkel gear.....it was like nothing i have ever done and having someone else cook and clean while I camp was well worth it. YOu need to do this in the Jan-March...but they offer other trips in Alaska, Costa Rica and Pacific Northwest which were also very good. They are located out of Friday Harbor in Washington.