"Now is the ideal time to pick up shares of high-quality European companies; not only are valuations attractive at these levels, but earnings could also surprise to the upside in an environment where global growth remains strong," says international specialist Yiannis Mostrous.

The contributing editor to Personal Finance explains, "Once such top European bargain is water and waste-management firm Veolia Environement (VE).

"Europe accounted for three-quarters of Veolia's revenues in 2009, with France accounting for roughly half that total. But the company's main business lines have relatively light exposure to economic cyclicality and may benefit from European austerity.

"Warren Buffett's Berkshire Hathaway revealed a new position in Nalco Holding (NYSE: NLC); it's my favorite pure play on water filtration," says Chris Mayer in Daily Wealth.

"With a $1.6 billion market cap, Nalco is a small-cap stock, but it's actually one of the world's largest water-treatment companies. Customers use Nalco's products and services to prevent corrosion, contamination, and the buildup of harmful deposits.

"Buffett picked up 8.7 million shares. That makes Berkshire the second-largest shareholder in the company, with a little more than 6% of the shares.It's easy to see what Buffett likes.

This post is part of a special annual report -- Top Stock Picks '09 -- in which TheStockAdvisors.com asked 75 leading newsletter advisors to select their favorite investment for the new year.

"As the government and corporations look to get more environmentally sound, they'll be turning to Tetra Tech (NASDAQ: TTEK), an environmental consulting company," suggests 'green technology' specialist Brendan Coffey.

The editor of The Cabot Green Investor explains, "Tetra Tech is the expert people turn to the figure out the nitty gritty of getting eco-projects done." Here's his review of the stock, which he selects as his favorite investment idea for the coming year.

"President-elect Obama looking to resuscitate the economy, wants to do two things at once: immediate stimulate job growth with an aid package of perhaps $700 billion while laying the groundwork for the country's long-term economy health.

"He's identified the core of that dual strategy as going green -- to wean us off oil, counteract the eventual dire effects of global warming and make the country the technological leader in alternative energy, creating five million or more jobs in the process.

Two leading global experts have both turned bullish on France's Veolia Environnement (NYSE: VE). Vivian Lewis, in her Global Investing, notes, "Veolia is the way to play the 'water works square' on the monopoly board."

Nicholas Vardy, editor of Global Stock Investor suggests, "The smart money is betting that water may be the 'oil of the 21st century.' And Veolia is my number one way to profit from this global megatrend."

Vivan Lewis says, "We recommend buying French water and sewage conglomerate Veolia at current prices; the stock has been brought down by niggling Euro-concern about its levels of debt. The company is also being penalized for acquisitions.

"Veolia is the former Générale des Eaux, a municipal service firm. This history creates an image problem for VE which is seen as a utility.

"Our main reason for the buy, apart from price, is that this is a fast growing company with good earnings in a hot sector. In 2007, VE had revneues of euros 32.6 bn, up 14% on which its recurring net profit fost 22.5% to euros 933.2 mn. Earnings per share were euros 2.16, up 13.7%.

"Another reason for liking VE is that it is moving into China big-time, with waterworks in Tianshin and Shibai and environmental service in Juijiang. All in all, France still represents 44% of sales and the rest of Europe 36%. VE does about 10% of its business in the U.S. and the Chinese are part of the remainder.