Newsweek has released its annual countdown of the 100 most environmentally conscious companies in the U.S. -- excluding some of the usual suspects, and including several surprising and unlikely choices. Green businesses are good news for investors, since eco-friendly companies are often better able to cut waste and boost innovation and productivity going forward.

To compile the list, Newsweek first rounded up the largest 500 companies in the U.S. measured by revenue, market cap, and number of employees. Then Newsweek and its partners at MSCI ESG Research, Trucost, and scored these companies on various environmental metrics.

Here are the magazine's top 10 greenest of the green:

  • Dell (Nasdaq: DELL)
  • Hewlett-Packard (NYSE: HPQ)
  • IBM
  • Johnson & Johnson
  • Intel (Nasdaq: INTC)
  • Sprint Nextel (NYSE: S)
  • Adobe Systems (Nasdaq: ADBE)
  • Applied Materials (Nasdaq: AMAT)
  • Yahoo!
  • Nike (NYSE: NKE)

Environmental concerns are fast becoming serious business for companies and shareholders alike. Amid mounting evidence that environmental damage represents a hidden cost that could hurt wealth and prosperity, the search for sustainable innovation is on at many major U.S. companies. Meanwhile, shareholder-driven climate-change proposals at public companies increased 40% from spring 2009 to spring 2010.

Green companies aren't simply catering to environmentally minded shareholders. It's not rocket science for any long-term investor to realize that devising better, less wasteful ways to do business can help companies rack up big savings -- and more profits. To misquote Gordon Gekko, when it comes to capitalism, green is good.

What do you think? Sound off on publicly traded companies' green initiatives in the comment box below.