Whether it's the corporate lunchroom, your cubicle, or the local watering hole after work, there are regular places we gather to discuss news, sports, or -- if you're like us -- stocks. Here at Motley Fool CAPS, we gather around the virtual water cooler daily to rate stocks and delve into their merits as investments.

Our 160,000-strong CAPS community -- where members give the thumbs-up or thumbs-down to some 5,400 stocks -- seeks businesses it thinks will outperform the market. Below we'll take a look at some of the most popular and talked-about stocks in the CAPS universe and examine whether you think they'll continue their winning ways.

Stock

CAPS Rating (out of 5)

Number of Calls

% Outperform Calls

Berkshire Hathaway (NYSE: BRK-B)

****

5259

98%

ConocoPhillips (NYSE: COP)

***

5256

97%

Research In Motion (Nasdaq: RIMM)

**

5291

83%

Of course, just because a lot of investors find these stocks interesting doesn't mean they're an automatic addition to your portfolio. You still need to do more research to find out if they're interesting because they're set to take off, or because their stocks are ready for a trip to the cellar.

A tall drink of water
A lot of ink has been spilled over Warren Buffett's big bet on the U.S. economy, and he's also been the target of sniping by critics who believe his advanced age is catching up to him. Some of his investment decisions lately have left people scratching their heads.

Berkshire Hathaway loaded up on ConocoPhillips stock just as oil prices peaked, then he unloaded shares just as they bottomed. He bought Burlington Northern railroad, which some view as an archaic means of transportation, and did a 50-to-1 stock split of Berkshire's B class shares to complete the deal -- a move he's often derided as a meaningless gesture.

Considering Buffett's remarkable history and the fact he often confounds the analysts who don't understand him, I'm willing to wager that senility's not settling in. CAPS member JET79 would agree, enjoying the instant diversification an investment in Berkshire Hathaway gives him.

As for Buffett's bet on railroads that could be paying off handsomely soon, according to the Association of American Railroads, freight traffic was up for the fourth consecutive week, while the CEO of Norfolk Southern (NYSE: NSC) points to growth within the railroad's domestic intermodal business as proof they're outpacing the conventional trucking market. It was the benefits of carrying freight by rail compared to trucks that tipped Buffett into buying Burlington.

Although he might have erred in buying ConocoPhillips, he's also smart enough to realize when he has made a mistake and move to correct it. As the economist John Maynard Keynes famously said, "When the facts change, I change my mind. What do you do, sir?" 

Conoco lags behind ExxonMobil (NYSE: XOM) and Chevron, and it is still trying to correct for the foolhardy acquisitions it made in years past by getting rid of assets, yet that has some investors seeing it as a ripe opportunity to get back into the stock. CAPS member AjarnMichael believes a rebound in natural gas will help pump up the price, but he's willing to receive the healthy dividend while he waits for that to happen:

COP is very attractively valued. When natural gas and oil prices bounce back, COP is poised to benefit. Their recent efforts to reduce operating costs will payoff and in the meantime they offer a healthy 4% dividend.

A slick deal
One stock Buffett will probably never buy into because of his well-known aversion to technology issues is Research In Motion. But there's plenty of opportunity for other investors to reap the rewards of investing in the smartphone maker.

These days it seems it's the buzz is all about the iPhone, all day, every day. But RIM still commands the lion's portion of the smartphone market because unlike Apple (Nasdaq: AAPL), it has carefully catered to the enterprise segment of the market. Even the potential for a Verizon (NYSE: VZ) iPhone should merely convert dissatisfied AT&T customers rather than steal customers from the BlackBerry.

While the competitive challenge has Prodders thinking it will be beleaguered by pricing pressure, MissionAlf  believes its market dominance will remain unassailed, particularly as China Telecom unveils the BlackBerry to the biggest mobile phone market:

Palm is dead... and rightly so! RIM has consistently outperformed and beat estimates. They now own 43% of the smartphone market and that's not going to change with China getting their phones. Look for another beat on their fourth quarter results in a couple of weeks. They are on the way up!

Gather 'round
With so many good opinions about today's top companies, why not grab a pointy paper cup from the dispenser and join us at the Motley Fool CAPS watercooler? Your input can help guide other investors to stocks with bright prospects for growth. Read a company's financial reports, scrutinize key data and charts, and examine the comments your fellow investors have made -- all from a stock's CAPS page.

Sign up today for the completely free service, and let us hear what you have to say about the great and almost-great companies that interest you.

Berkshire Hathaway is a Motley Fool Inside Value selection. Apple and Berkshire Hathaway are Motley Fool Stock Advisor recommendations. The Fool owns shares of Berkshire Hathaway. Try any of our Foolish newsletter services today, free for 30 days.

Fool contributor Rich Duprey does not have a financial position in any of the stocks mentioned in this article. You can see his holdings. The Motley Fool has a disclosure policy.