Since I live in the Southwest, any place that has a nice stream flowing through it! I prefer riparian areas in the canyonlands of northern Arizona or southern Utah. Here, you have your water needs met, good fishing, excellent foraging opportunities for edible plants, and often a landscape peppered with ancient ruins as this is where most prehistoric cultures resided. In the summer, an elevation of 4,000-6,000 feet is ideal as it is usually not extremely hot during the day and nights are balmy.
On these personal trips that range from 3-10 days, I take a wool blanket, knife, cooking pot, water bottles, and a small bag of rice and oats. Everything else is obtained from the landscape in a mindful way--taking from abundance and leaving abundance.
I also like southwestern Colorado as this region has fewer crowds than the northern portion of the state, numerous hot springs, mountain streams, and fields of wildflowers. It's a nice escape from the heat of the desert when Arizona temps spike.
When I head out on a personal walkabout, I strive to connect with the natural world using traditional skills so it is not so much of a "survival" or endurance trek as it is a means of relying upon my hands and the old ways in a manner that is respectful of the land. Survival by it's very nature usually implies suffering and hardship. My walkabouts emphasize traveling lightly across the landscape while rekindling that ancient bond to the wild, something that all of us have in our heritage. The Southwest enables me to see that connection more clearly as myriad ancient cliff dwellings and present-day native cultures, like the Hopi, with their tremendous history and ecological knowledge underlie generation upon generation of listening to the land.