The top contender on this year’s list of Fortune’s Fastest Growing Companies may surprise you.

Research in Motion was ranked number one on the list, with a three-year average earnings-per-share growth of 84 percent and revenue growth of 77 percent. Shares of RIM have a three-year annual total return of 45 percent.

Apple, which is three times the size of RIM in sales and market value, only came in at number 39 on the list. In fact, IDC recently reported that the bestselling smartphone in America so far this year by units is not the iPhone, but the BlackBerry Curve, which is made by RIM.

RIM has a 56 percent share of the $12 billion U.S. smartphone market. During the past 10 years, the company has sold about 65 million phones to its 28.5 million subscribers, increasing its stock market capitalization from $96 million to $42 billion.

Even though the BlackBerry was once considered a business tool, it has made large gains as a consumer product, and now appeals to many markets and age groups. During Q4 2008, 80 percent of the company’s new subscribers came from the non-business crowd, which could have something to do with the company launching its first television campaign targeting a mass audience at the same time.