Ten bucks says you can't inventory your closet in much detail -- clothes, shoes, maybe a baseball bat or two. But what's lurking in the dark corners of your personal space? Even worse, do you know how long it's been hiding there?

We all have a few long-forgotten collectibles gathering dust in our closets (right next to the skeletons). Some of these odds and ends may not be so scary, though, and could be quite valuable. Similar experiences can be had rummaging through the stock market closet -- investors may be quite surprised to find what's there. And even more surprised to discover how much it's worth.

Hiding in dark corners
Imagine it's 1982 and you've received a gift of a few shares of J.C. Penney (NYSE:JCP) from your Uncle Joe. You file it away appropriately (where you'll never find it, of course). Flash forward 25 years: You're cleaning out the closet, and you stumble across those shares. If Uncle Joe had bought you $1,000 worth of JC Penney stock at the time, you'd now be sitting on a plump $80,000. Not a shabby reward for being forgetful and untidy, eh?

There are literally hundreds of companies out there like J.C. Penney -- familiar, well-managed organizations that don't exactly set investors drooling with visions of great wealth. That's too bad -- some of these drab closet-dwellers pack a powerful punch. Consider some other companies lurking in dark corners but generating amazing returns:

Who would've thought that sweaty, smelly pieces of rubber and synthetic leather could be transformed into a fashion statement? Nike has done an incredible job of taking shoes from a commodity item to a premium product, rewarding long-term investors along the way. Since going public in 1987, Nike has returned more than 6,200%, or roughly 23% annually, for shareholders. Younger competitors Sketchers USA, Deckers Outdoor, and Crocs are all kicking for their turn as a world footwear giant.

Dick's Sporting Goods (NYSE:DKS)
From tennis to lacrosse to wakeboarding, Dick's carries everything that a sports enthusiast could possibly fit in a closet. The retailer of sporting equipment and clothing has been posting solid growth for several years, rewarding shareholders with a 630% gain since going public in 2002. Smaller competitors such as Motley Fool Hidden Gems recommendation Cabela's (NYSE:CAB) and Big 5 (NASDAQ:BGFV) hope to mimic Dick's success and carve out their own profitable corner of the sporting goods market.

Cherokee (NASDAQ:CHKE)
Rather than manufacture its own merchandise, Cherokee licenses branded clothing to major retailers such as Target (NYSE:TGT). Simply licensing popular brands such as Cherokee and Sideout keeps margins sky-high, generating plenty of cash for the company. This closet-dweller has kept shareholders happy, too, returning a whopping 8,600% since going public in 1995.

Come out of the closet
These companies show that great things can come from commonplace sources. Each has a similar story -- they started as small and little-known companies, led by founders who focused on steadily dominating a product niche with wide consumer appeal. Nothing too flashy or fancy; just steady growth on the top and bottom line, thanks to efficient management.

While some investors spend hours scouring all sorts of industries for great stocks, many know they only need to go as far as their closet to find some killer companies. Unafraid of facing the boogeyman, Motley Fool Hidden Gems lead analysts Tom Gardner and Bill Mann dig through musty closets to find monster stocks with similar traits, long forgotten or overlooked by many investors. Click here for a free 30-day trial, and see what surprising winners they've come across.

Fool contributor Dave Mock is more worried about what lurks in the back seat of his car than his closet. He owns no shares of companies mention in this article. The longtime Fool is the author of The Qualcomm Equation. The Motley Fool's disclosure policy keeps a flashlight under the bed, just in case.