I use this since I refuse to put anything on my skin that melts plastic
http://www.vitacost.com/all-terrain-natural-herbal-armor-insect-repellent?csrc=GPF-PA-608503010030&ci_sku=608503010030&ci_gpa=pla&ci_kw=%7Bkeyword%7D&gclid=CMuY1qujqbICFSdgMgod5i0AXg
My top three:
Denali - The best true wilderness experience by a long shot.
Big Bend - Very underutilized (i.e. not crowded). Beautiful landscapes and stark contrasts between desert and mountain areas.
Volcanos National Park - The closest you will probably get to walking on a moonscape.