This post is part of our Battle of the Brands feature. Let us know which brand you prefer, and watch out for more Battle of the Brands posts.

There exists, somewhere between the fearsome mass-ness of the mainstream grocery store and the high-pitched good works of the coop, farmer's market, or CSA, a world in which low prices are valued slightly higher than locality of the source but, more than anything, the products must be good. Fair-trade, organic, without trans-fatty acids, with fewer artificial colorings or preservatives or Disney characters than all the other products.

It's the world of the natural foods market. A world dominated by two very dissimilar and yet, from a target market perspective, nearly identical competitors: Whole Foods Market, Inc. (NASDAQ: WFMI) and Trader Joe's, a unit of German private company Aldi Group.

Walking into a store -- or simply gazing at one from across the street -- you have a very different picture. On one corner, in the midst of a posh shopping area or trendy boutique-spattered neighborhood, Whole Foods, with its glistening crates of fresh produce, honeydew melons, purple potatoes, and blood oranges piled high in an abundance of exoticism. The doors open smoothly, the merchandise is displayed beautifully, and a high-ceilinged eating area is often overflowing with customers enjoying their deli purchases. Customers enter slowly, looking around as if discovering a stunning architectural landmark for the first time.