Which stocks were the best performers over the past decade? Brazilian oil giant Petrobras (NYSE:PBR) put up a mighty fine 538% and PepsiCo's (NYSE:PEP) 73% return wasn't too shabby, particularly when you compare it to the overall market's terrible returns.

But these two were nowhere near the top performers of the past 10 years. That list is made up of rocket shots like Medifast (NYSE:MED) -- which put up returns of more than 16,000% -- and Clean Harbors, which was up 4,667%.

So what allowed the second duo to deliver such clobbering gains? A lot of things are likely at play, not least of which are a good business and great execution. But the second two stocks share something else important -- they're tiny and not very well known.

My fellow Fools -- particularly the team at Motley Fool Hidden Gems -- are well-acquainted with the fact that smaller stocks that haven't been discovered by Wall Street have a tendency to blow past their larger brethren.

So where do we start if we want to find the stocks that will put up market-annihilating returns over the next 10 years? I turned to the 145,000-member Motley Fool's CAPS community. Below I've pulled up five stocks that have market caps of less than $1 billion and have been highly rated by CAPS members.

Company

Market Cap

Projected Long-Term Growth

CAPS Rating
(out of 5)

Energy Conversion Devices (NASDAQ:ENER)

$515 million

18.3%

****

Western Refining (NYSE:WNR)

$459 million

4.1%

*****

Taseko Mines (NYSE:TGB)

$784 million

NA

****

China Fire & Security Group

$395 million

17.5%

****

PetMed Express (NASDAQ:PETS)

$414 million

14.8%

*****

Sources: CAPS and Yahoo! Finance.

While these aren't meant to be formal recommendations, they could be a great place to kick off further research. In fact, let's go ahead and take a closer look at a couple of these companies.

Gold from Prosperity
Taseko Mines has historically focused on mining copper and molybdenum from its Gibraltar mine in British Columbia. But if all goes according to plan, that could soon change.

The company hopes its Prosperity venture is auspiciously named and believes that the massive gold and copper project could be a huge boon for shareholders. As of November, Taseko estimated that the Prosperity project had proven and provable gold and copper reserves of 7.7 million ounces and 3.6 billion pounds, respectively.

The best part about Prosperity? As my fellow Fool Christopher Barker spelled out in December, the market may not be attributing any value to the project. If this turns out to be true, this could be a small cap that will be on everyone's radar really fast once Prosperity comes online.

Prosperity from pets
PetMed Express may not be sitting on a massive gold mine, but the stock could nonetheless be a small but mighty portfolio addition.

PetMed -- which consumers probably know better as 1-800-PetMeds -- is a nationwide leader when it comes to delivering pet medications to consumers who order via the phone and Internet. Between the company's 2005 fiscal year and the past 12 months it has seen sales jump 113%, and its net margin expanded from 7.4% to 10.8%.

And the best may be yet to come. The market for pet products is one that has been bolstered in recent years as pet owners all over the country become increasingly focused on making sure their four-legged friends get high-quality care.

And I'm not the only one who thinks highly of PetMed Express. CAPS member mistercube joined the 734 other PetMed fans on CAPS in early December and painted a pretty bullish picture for the stock:

A victim of the broader economic downturn, this company has managed to grow earnings and initiate a dividend while blue chips have seen profits disappear. I like this almost as much for the apparent low risk as for the growth potential.

Make your call
The CAPS community is all about getting everyone's opinion into the mix. Head over to CAPS and let the 145,000 members know what you think about Taseko Mines, PetMed Express, or any of the other stocks listed above.

Want to read more about small companies that could make you an investing big shot? Check out fellow Fool Anand Chokkavelu's thoughts on the stocks that could be 2020's 10-baggers.

Petrobras and PepsiCo are Motley Fool Income Investor picks. Try any of our Foolish newsletters today, free for 30 days

Fool contributor Matt Koppenheffer does not own shares of any of the companies mentioned. You can check out what Matt is keeping an eye on by visiting his CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool. The Fool's disclosure policy has never once been caught with its pants down. Of course, it doesn't actually wear pants ...