Our very best vacations have been Hawaii (rented a house) and the beautiful beaches there. Snorkling, swimming, touring a lava tube, seeing volcanoes, going to the top of Mt Haleakala. Our kids loved it!
Maine - we rented a beach house in a small town. It was gorgeous. One beach nearby was a sand beach. The other beach you had to hike to and it was a rock/pebble beach. At low tide you could hike out to a little island and explore it. This was magical for the kids!
Camping at the Grand Canyon. The kids had a BLAST. My oldest brought his bike and rode it around the campsite. We had so much fun doing hikes, riding mules, eating good food, making a campfire every night.
We had one vacation in Moab...we went mountain biking (on easy trails bc our youngest would sit in her bike seat) which our kids LOVED. We hiked/explored at Arches Nat'l Park which our kids also loved.
We do ski vacations each winter...there are a gazillion ski areas within a day's driving distance from here. Our ski passes are good at 7 different ski areas, so we go to each one each year (if we can make it work). The kids love it. Our 3 year old was skiing on her own by the end of last year which was amazing to me.
Last summer was one of our best vacations ever. We flew to Juneau, Alaska (where we used to live). Rented a car, and took it on the ferry to Haines. Then we drove up into interior Alaska, visited my brother, camped, and saw the sights. The kids had such an amazing time...they got to canoe, pick berries, see glaciers, see all kinds of wildlife, go to national refuges and state and national parks. All of us agree the most amazing part of the trip was Wrangell-St. Elias National Park and the Kennicott mine. WOW. Truly incredible.