Their statuesque oldest daughter, Malia, sports a Hawaiian name that's a variant on Mary, and means "bitter." Malia comes paired with the classic middle name Ann, which means "grace." Malia is a nice nod to both Barack's Hawaiian roots and to Michelle's mother Marian (who herself boasts a variant on the classic Mary). Malia is currently hovering around the top 300 mark, and makes a nice alternative to uberpopular names like Maya and Mia.
And the Obamas' vibrant younger daughter, known as Sasha, was actually given a longer name, Natasha—and one that doesn't appear to be pulled from their family tree. It's a Russian name that means "Christmas Day," while Sasha, which is also Russian in origin, means "defender of men." Natasha's currently on a bit of a down slope here in the U.S., but Sasha got a boost on the baby name charts when Obama was first elected—I'm wondering if this second term will bring a new wave of Sashas to our shores. (By the way, Sasha also makes a nice boys' name, as that's how it got its start.)
Both names have a nice cadence with their last name, with matching "ahs" at the end of each name.
Obama Family Portrait, courtesy of whitehouse.gov