I have a few, but my top one (strangely enough) is at Fort Wilderness. After 2 or 3 days of theme parks and crowds, I always love to spend a relaxing day at Fort Wilderness driving the Sea Raycers, going for a bike ride, canoeing along the canals, and just walking around. It's a great recharge, and I love the natural beauty.
Another of my favorite spots is in the Africa section of DAK. I love DAK because it is, IMHO, the most beautiful theme park anywhere. The Africa section is especially great because of all the intricate details on the buildings as well as the lush greenery. Its always a great spot to stop and have a bit to eat, relax and people watch.