16. Woodman Labs, the maker of GoPro, is valued at $2.3 billion.

Nicholas Woodman and GoPro have come a long way since the camera startup's inception in 2002. More than a decade later, GoPro is gearing up to go public.

Last year, GoPro made nearly $1 billion in sales. In 2012, GoPro made $521 million in sales with a valuation of $2.3 billion.

GoPro is expected to publicly file its initial public offering in May or June.