10.Marissa Mayer

Marissa Mayer

CEO, Yahoo
--Cultural impact
--Most Powerful Women
--40 Under 40

She bought Tumblr for $1.1 billion and revamped Yahoo Mail and the company's Flickr photo-sharing site. And though Mayer's overhauls (from products to workplace policies) stir controversy, she has lifted Yahoo's (YHOO, Fortune 500) user base to 800 million while the stock price has almost doubled this year. Those accomplishments help explain why Mayer, 38, has achieved an unprecedented trifecta: the only executive ever to earn a spot on the Businessperson of the Year list, Fortune's Most Powerful Women list (at No. 8), and Fortune's 40 Under 40 rankings (No. 1).
--P.S.

9.Warren Buffett

Warren Buffett

Chairman and CEO, Berkshire Hathaway
--Cultural impact
--Returnee

He began the year devouring H.J. Heinz, the world's largest ketchup maker, for $23 billion, in partnership with Brazil-based 3G Capital. Now Buffett sits on more than $40 billion in cash, thanks in part to his gutsy investments in companies like Goldman Sachs (GS, Fortune 500) and Bank of America (BAC, Fortune 500) when others panicked during the 2008 financial crisis. As Buffett's pile of cash grows, it's ever more likely that Berkshire (BERK) will make another big acquisition. The Oracle of Omaha hit another milestone this year. In May he joined Twitter and already has over 700,000 followers.
--Patricia Sellers

8.Larry Page

Larry Page

8

Co-founder and CEO, Google
--Cultural impact
--Returnee

Page's seemingly paradoxical formula to re-energize Google (GOOG, Fortune 500) -- more focus and more moon shots -- is paying off handsomely. Shares this year passed the $1,000 mark, pushing Google's value ahead of Microsoft's and behind only Apple's and Exxon's (XOM, Fortune 500) among U.S. companies. As if making sure Google stays No. 1 in search, ads, mobile, online video, maps, browsers, and more was not enough, Page has launched Google's latest zany venture: an anti-aging startup named Calico.
--Miguel Helft

7.Akio Toyoda

Akio Toyoda

CEO, Toyota
--Turnaround story

The Toyoda scion says he follows two rules: "Make ever better cars. And if it doesn't offer fun, then it is not a car." He's succeeding on both counts. Just a few years after the company suffered an embarrassing recall that left a trail of lawsuits (plus the aftermath of a devastating tsunami), Toyota (TM) is back. Toyoda is steering his family's company toward record-high sales of 10 million cars and trucks, as well as record high operating profits, keeping it No. 1 in the world. At the same time he's injecting much-needed flair into its vehicles' design and engineering.
--Alex Taylor III

6.Jeff Bezos

Jeff Bezos

Founder and CEO, Amazon
--Cultural impact
--Returnee

Bezos defied expectations again this year, sacrificing company profits nearly two decades after founding Amazon (AMZN, Fortune 500) to chase (and potentially corner) new markets. The Seattle-based company plowed ahead with its same-day grocery-delivery efforts and partnered with the ailing U.S. Postal Service to allow Sunday delivery in some U.S. cities. Bezos's boldest move? Buying the Washington Post for $250 million with his personal venture fund. Still, his eclectic strategy has paid off in the past, and Wall Street remains as bullish as ever on the stock, up some 40% year to date.
--JP Mangalindan

5.Reed Hastings/Jeff Bewkes (tie)

Reed Hastings/Jeff Bewkes (tie)

CEOs of Netflix and Time Warner

--Returnees
--No. 3 stock price gainer (Netflix)
It has been three years since Fortune named Reed Hastings businessperson of the year; shortly afterward, Jeff Bewkes, CEO of Time Warner (TWX, Fortune 500), compared Netflix (NFLX) to the "Albanian army" -- unlikely to take over the world. There's little dispute now that the business Hastings leads is ready for battle. Its programs are Emmy winners (House of Cards) and buzz generators (Orange Is the New Black), its stock price has soared (up 100% since late 2010), and for the first time it has more paying subscribers than HBO. But Netflix's encroachment doesn't seem to be cramping Bewkes's style these days: Time Warner stock has more than doubled in three years, and it is up 40% for the year, buoyed in part by the media giant's decision to spin off its Time Inc. publishing unit (Fortune's parent). Once he sheds Time Inc., Bewkes will be left with a more focused movie and television business, one that includes HBO. (He already hived off cable networks and AOL (AOL).) If Netflix is the Albanian army, Bewkes's Time Warner might well be the U.K. -- no longer a sprawling empire, but a prosperous place with a clearer sense of identity and purpose.
--A.L.

4.Angela Ahrendts

Angela Ahrendts

CEO, Burberry
--Most Powerful Women
--Returnee
Ahrendts was already having a banner year as the CEO of British fashion house Burberry. The stock was up 29%, vs. the FTSE 100's 10%, despite fears of a slowdown in greater China and continued ennui in Europe -- when she shocked the luxury and tech worlds with news that she was decamping to Cupertino, Calif., to head up Apple's retail and online stores. Ahrendts takes the reins in 2014, and she will oversee an operation with some $20 billion in annual sales (compared with Burberry's $3.2 billion). Analysts expect that she will play a role in helping define Apple's future, especially as technology companies move into new areas, such as "wearables" like Internet-connected watches, eyewear, and other gadgets that are in desperate need of a style makeover. (Ahrendts is credited with helping bring a more youthful image to the 157-year-old trench-coat maker.) Ahrendts's new role makes her the top woman exec at the house that Jobs built, and her success, while critical to Apple's future, will be no easy feat. The last executive to head up the tech giant's retail operations was out after less than a year. If she pulls it off, Ahrendts could be a strong contender for the top job.
--Beth Kowitt