Let's imagine that The Motley Fool gave you $100,000 to invest in your favorite stock two decades ago. We agreed to split the winnings after 20 years. Why? Because you're smart, you look like a million bucks, and you've got no detectable personal hygiene issues. We like you. We believe in you.

The year is 1988. A hundred thousand bucks has your nerves on edge, so you pop a Michael Bolton cassette into your Walkman (from before he went adult-contemporary) and cruise to the local cinema to catch the matinee of Bruce Willis' new flick, Die Hard. Three hours later, kicking past a strip mall of Thom McAn, Arthur Treacher's Fish & Chips, Bradlees, and Crazy Eddie, you have an idea.

You'll ask Gramps for his favorite stock, then you'll ask your cousin Marilyn Meeker for hers. Gramps was a banker for 41 years. Marilyn's getting a business degree. You'll get two different perspectives. Good plan.

Two roads diverged
Over finger sandwiches and Canada Dry on the patio of your grandfather's country estate, he raises a crooked index finger to the sky and says simply, "Eastman Kodak (NYSE:EK). The stock's a stalwart. It's up 150% for me over the past 20 years. A nice, conservative pick."

A few days later, hammering away at a Galaga machine at the local arcade, your cousin rattles on about a small-cap stock. "It's a new issue," she says. "Dell (NASDAQ:DELL). It makes computers that are compatible with IBM (NYSE:IBM) PCs. If you've got 20 years, go with a solid small company like Dell. It's in a great industry and its founder and CEO owns a ton of stock."

After a few hours of reflection, you rotary-dial your Motley Fool contact with this directive: "For the next 20 years, I say put that $100,000 into _______."

Which?

The 20-year mark
Since 1988, Eastman Kodak is actually down about 50%, for a miserable average yearly loss of 3.4%. Against that, Dell is up 100 times in value. With Kodak, your $100,000 has turned into just over $50,000. With Dell, it's swelled to $10 million. That's the difference between thousands and millions for long-term investors.

At Motley Fool Hidden Gems, we search for these multimillion-dollar opportunities by analyzing promising small-cap growth stories like Ctrip.com (NASDAQ:CTRP) and Natus Medical (NASDAQ:BABY), while avoiding overgrown giants like General Motors (NYSE:GM) and AT&T (NYSE:T).

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