The stuff being sold as "moonshine" at the liquor store that I have seen is either unaged whiskey, sugar liquor, or a combination of the two. It comes off the still at somewhat lower proof than vodka to retain some of the flavors of the source material. A local distillery owner said on a tour that when they mess up making a batch of whiskey or rum they end up with vodka as it doesn't take much effort to keep distilling it until it reaches the azeotropic level of about 95% alcohol.
I've tried quite a few of them. The ones I liked were Dickel no 1 corn whiskey, American Born Moonshine, and Ole Smoky Mountain Moonshine. There are many I have not tried. I won't pay a lot for whiskey that hasn't seen the inside of a barrel. It's one of those spirits that, to me, really benefits from the maturation process.