World’s Greatest Leaders: 9 dynamic duos

Power couples don't get any bigger than this. Former titles held by Bill (#5) and Hillary: President; Secretary of State; Senator; Governor. And of course the two joined forces more recently to steer The Clinton Foundation, which is taking on a number of intractable problems across the world from climate change to poverty to the spread of HIV/AIDS. The foundation's strategy is to bring together all stakeholders—from governments to NGOs to businesses—a task few are more capable and skilled at doing than the Clintons. The pair is also doing what it can to inspire and train the next generation of leaders and global citizens: this weekend, they'll host 1,000 students on the Arizona State University campus as part of the Clinton Global Initiative University.

Gabrielle Giffords, 43, and Mark Kelly, 50

Co-founders, Americans for Responsible Solutions

Giffords (#24) and Kelly both have personal histories of leadership—Giffords as an Arizona Congresswoman and Kelly as a former astronaut and Navy Captain—but the husband-wife team have teamed up for their latest project, an effort to get politicians to actually do something about America's gun violence problem. While Giffords is one of the country's best known victims, it was the tragedy in Newtown and the inaction of political leaders in its aftermath that inspired Giffords and Kelly to found their Super PAC, Americans for Responsible Solutions (ARS). As gun owners and 2nd Amendment supporters who also believe in gun control, the married couple has given voice to a large population that has nonetheless been silenced in America's polarized gun rights debate. And the money talks: in 2013, ARS raised $12 million—more than any other Super PAC—funds that are likely to be deployed during campaign season later this year.

Ted Olson, 73, and David Boies, 73

Superlawyers

Once-opposing gladiators in the rancorous Bush v. Gore case that ended the 2000 U.S. Presidential election, super lawyers Ted Olson and David Boies turned themselves into living symbols of bipartisan consensus. They joined forces to successfully strike down California's law against same-sex marriage, and are now taking on Virginia's.

Bill, 58, and Melinda Gates, 49

Co-founders, Bill and Melinda Gates Foundation

"We come at it from different angles," says Melinda about the philanthropic partnership with her husband: Bill leans on data, and she on first-hand field experience. "We add to each other," Melinda says, noting that they've strengthened one another's leadership. Bolstered by Warren Buffett's annual donations as well, the couple has given away more than $28 billion since creating the Gates Foundation 20 years ago. On a mission to reduce inequities around the world, Bill and Melinda divide and conquer: They typically travel separately (though they are planning a trip to India together this year). He spends two-thirds of his time on Foundation work (and one-third advising Microsoft) and is focusing on polio eradication. Melinda's No. 1 cause: family planning throughout the developing world.

Glen Greenwald, 47, and Laura Poitras, 52

Journalist/Documentary Filmmaker

Public conversation changed the day Edward Snowden fled the country with his computer and more than a million classified government documents last April. The many revelations that have come out since—about what exactly the NSA (and its foreign counterparts) had been up to in terms of spying, surveillance and data collection—have prompted serious thinking and heated debate among governments, businesses, and citizens. Credit for this belongs as least as much with Greenwald and Poitras, the journalists to whom Snowden turned and who have been on the case for years. Their fierce and dogged efforts to get the word out have not been without sacrifice (not to mention heightened scrutiny in airport security lines): Greenwald now lives in Brazil; Poitras in Berlin.

Jacqueline Novogratz, 53, and Chris Anderson, 57

Social Entrepreneurs

She's changing the way the world tackles poverty. He's ushered in a whole new (digital) era of thought leadership. Novogratz and Anderson, married since 2008, might not be household names but their respective non-profits are blockbusters: Novogratz, a banker-turned-global-do-gooder founded, in 2001, Acumen Fund (now Acumen), a social impact investor that helps businesses develop more efficient, sustainable solutions to poverty. And Anderson, a former journalist who took the reins at TED that same year has turned the organization into the buzzy, worldwide idea circuit it is today.

Beyoncé, 32, and Jay-Z, 44

Megastars

Trendsetters and business innovators, the influence of this celebrity power couple—dubbed "American royalty" by some—is hard to dispute. It may be because the entrepreneurial superstars wield far more careful control over their stardom than most. In December, when Beyoncé (her current world tour is called "The Mrs. Carter Show"—a nod to her husband, whose real name is Shawn Carter) surprised the world with her latest album, she bypassed the process of the music industry, and announced its release on Instagram. The strategy was to engage directly with fans, and it worked: the album broke sales records. And of course, they're just inspiring: Beyoncé has become a symbol and advocate of lady empowerment and Jay-Z, whose life got off to a rough start in a Brooklyn housing project, has built a business empire.

Tina Fey, 43, and Amy Poehler, 42

Comedians

Every so often—like in 2007, when Christopher Hitchens declared it so, or in 2012, when comedian Adam Carolla did—the territorial claim that "women aren't funny" rears its ugly head. While that's always been baloney, perhaps never before has it been so easy to laugh off. Fey and Poehler, who are close friends going back to their days working on Saturday Night Live, are the creative talents behind hit network sitcoms—the recently re tired 3 0 Roc k and Parks a nd Rec (also two of the very few hit network sitcoms in recent memory)—are center stage these days. Quite literally: they hosted the Golden Globes together in January. But that means more than great entertainment and an end to a dumb argument; Fey and Poehler have helped pave the way for women in the industry (there's a bumper crop now) and beyond—rejecting the old, but entrenched stereotypes of how women should be.

Alan Khazei, 52, and Vanessa Kirsch, 48

Social Entrepreneurs

Married couple Kirsch and Khazei have both made their life's work about engaging young people and improving civic environments. As a Harvard law student, Khazei co-founded City Year, a year-long service program for young adults that later became a model for AmeriCorps. While he has remained an active advocate for a national year of service—he successfully helped save AmeriCorps from an 80% funding cut in 2003—he now heads up Be the Change, which builds coalitions to effect policy and cultural change. Kirsch, whose second social entrepreneurial venture also served as a model for AmeriCorps, went on to found a third, New Profit, a non-profit that helps successful social entrepreneurs increase the impact and scale of their organizations.