Actually, my favorite place to vacation is my home state, Arkansas. I was born there, and I lived there on and off until I was 14 or so. I've been to a decent amount of places in the U.S (Though I'd absolutely love to see Europe) and there's none better in my opinion, espescially in the west-central part where I'm from.
Forests and mountains as far as the eye can see, plenty of out-of-the-way backroads in the mountains to drive, lots of rivers and lakes and parks, you're never short of anything to do. You can find a place on one of those backroads, and just be at peace for hours, taking in all the wonders of the nature around you, and chances are very good you will be the only person around for miles the entire time. Find some great country cooking at the restaurants in the small towns that sparsely dot the area. The climate can be a little weird, but not as bad as Texas (If you've lived in Texas, you know what I'm talking about.) Most of the time it's pretty pleasant out. Ah, my happy place. I'm actually saving up right now to move back out there for good, hope it won't be too much longer. 🙂