Most investors will be happy to put the last decade behind them. But for a few smart money managers, the past 10 years have provided a chance to show off their ability to invest profitably even in tough market environments.

A lousy benchmark
We all know firsthand just how bad things have been for U.S. stocks since 2000 began. Coming off the height of the tech boom, stocks could only maintain gains for a few months after the millennial celebrations before starting to collapse. After a two-year bear market, stocks spent the next five years retracing their steps and eventually making new highs -- before again succumbing to the financial crisis and an even bigger drop in stocks.

But things weren't nearly as bad for other types of investments. International stocks put in better performance throughout the decade, and stock markets in emerging-markets countries did particularly well. Moreover, bond investors reaped the benefits as investors fled from the stock market, pushing bond yields down and prices up.

So gains weren't unheard of among rank-and-file mutual funds investing in these and other areas. However, the returns that a few top professionals managed to earn since 2000 were truly astounding -- and many investors hope that their magic will keep working into 2010 and beyond.

Meet the decade's best managers
Earlier this week, Morningstar announced its picks for the best fund managers of the decade. With one pick for each of three major asset classes -- bonds, U.S. stocks, and international stocks -- the winners were all people who have both put in great performance and have made waves throughout the investment world recently.

The bond-fund winner was absolutely no surprise at all: Bill Gross, manager of the $200 billion PIMCO Total Return fund. Gross has made as many headlines lately for his stock commentary as for his bond-fund performance. He's an outspoken skeptic about the stock market rally, and he believes that stocks will have a much rockier ride in the coming years. Realizing that yields on short-term bonds are insufficient for income investors, he suggested that utilities and telecom stocks might be a better place to get higher payouts. With dividends on companies like Duke Energy (NYSE:DUK), Exelon (NYSE:EXC), and even AT&T (NYSE:T) giving shareholders yields well above the typical stock or bond right now, that seems like a reasonable call -- even if Total Return shareholders won't benefit from stock picks.

This fund is more than fair
The domestic category winner was Bruce Berkowitz of the Fairholme Fund, which sported an average annual return of more than 13% versus the small loss for the S&P.

Berkowitz sports a variety of strategies that have worked well for him. Early in the decade, he avoided the tech bust with old-economy stocks like Berkshire Hathaway (NYSE:BRK-A). But he wasn't content to mirror the Oracle of Omaha's strategies. Instead, he took advantage of changing trends to make further gains. His fund moved into energy stocks, but got out of them before 2008's crash. More recent holdings like Pfizer (NYSE:PFE) and Boeing (NYSE:BA) weren't among 2009's best performers, but they're also better poised for big gains when their sectors come back into favor.

Out-of-this-world returns
On the international side, Oakmark's David Herro took top honors. A value investor, Herro went against the grain by buying shares of luxury retailers like Signet Jewelers (NYSE:SIG) during late 2008, when most investors were shunning any business that relied on rich consumers to spend.

Herro's small-cap international fund is among the pioneers of that asset class, which only now has started to attract mainstream investor attention. Although the Oakmark manager pays close attention to emerging markets, you'll find a lot of old-world names among his holdings -- making it clear that Herro hasn't simply ridden the coattails of international markets, but has instead discerningly selected the cream of the crop.

Will they repeat?
The big question, of course, is whether these managers will keep producing outsized returns in the next decade. Ordinarily, that would be a dangerous assumption to make. Gross, certainly, has had an amazingly positive environment for bonds in which to invest -- one that could reverse itself in a hurry if bond rates start to rise.

For the stock pickers, though, I'm more optimistic. After all, both Berkowitz and Herro have been tested by two bear markets. Investors know what to expect from these managers in terms of how they'll react in any market environment. Although no one can be certain what the future will bring, I think betting on these winners to continue their hot streaks is more than just chasing performance.

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Fool contributor Dan Caplinger was in the running for the top-mileage convertible driver of the decade -- until around 2001. He owns shares of Berkshire Hathaway. Berkshire Hathaway, Exelon, and Pfizer are Motley Fool Inside Value picks. Berkshire Hathaway is a Motley Fool Stock Advisor recommendation. Duke Energy is a Motley Fool Income Investor recommendation. The Fool owns shares of Berkshire Hathaway and Fairholme Fund. The Fool's disclosure policy is the tops.