Plenty of companies want you to believe they've been doing their best to save the earth. But in the world of marketing -- which rivals nature itself for ruthlessness -- just looking green can be even better (and more cost-effective) than being green.

But with a bevy of watchdog groups now evaluating companies’ claims to environmental responsibility, it’s becoming increasingly difficult to greenwash. Greenwashing, the term used to refer to disingenuous claims of earth-friendliness, has thus become one of our favorite new buzzwords.

Here are Minyanville's picks for the 10 companies most likely to hug a tree with one arm -- while covering up an oil spill with the other.