Founder and CEO, Under Armour
Rank change: Up
Plank's sports-apparel juggernaut is on a roll: The stock is up 60% this year and sales are expected to hit $1 billion for the first time. You won't find Plank celebrating; he's too busy gunning for sales of women's apparel (25% of sales) to exceed men's -- most notably with a splashy ad campaign featuring skier Lindsey Vonn -- and pushing his new line of basketball shoes.
Tough love: "There is no time for 'loser talk' about the economy limiting growth," says Plank. "We have to go and grow!"
NEXT: 15. Wendy Clark
Last updated October 14 2010: 1:25 PM ET