"We go through thousands and thousands of photos, and for the top 10, we choose those who have a strong sense of personal style and were out and about and had a great fashion year," People style editor Clarissa Cruz said. "It's not in any order; it's people we love for different reasons." 

For Winslet, it was her strong, saturated color palette and emphasis on sophisticated lines that won People over.

"I think Kate is very glamorous and appropriate at the same time," Cruz said. "She knows what works for her. She doesn't like going for the bubblegum colors; she went for darker, more elegant colors."

Despite the recent flak first lady Michelle Obama endured for donning a pair of moss-colored cotton shorts on a family vacation, it's exactly that sense of accessibility that got the mother of two back on People's Best Dressed List for the second year in a row.

Fashionista.com editor Abby Gardner couldn't agree more with Obama's "most accessible glamour" title.

"I'm a big fan of J. Crew, and that's something everyone relates to," Gardner said, "and the American designers she chooses to wear are some of the best of American sportswear. She definitely is the most impactful dresser in America right now, because she's moving merchandise, she's selling things out."

Gardner singled out another one of People's "best dressed," Beyonce Knowles, for her MTV Video Music Award red carpet look, but Knowles also takes her glamour to the streets.

"It's not easy to look great every time you leave the house," Cruz said of the singer, whom People added to the list for having the "best street chic."

"Beyonce wears belts that emphasize her small waist and her curves. She always looks great when she leaves the house because she always has great hair and makeup, and almost always is wearing high heels," Cruz said.

Petite actress Reese Witherspoon made the list for "best short dresses," like the green and silver Rodarte the 5-foot-2 star wore to the March premiere of "Monsters vs. Aliens."

"I love that they included Reese Witherspoon in the Rodarte dress, because that was a big moment for Reese," Gardner said. "Reese always looks great, but she's never really stepped outside of classic dresses. Rodarte are the darlings of the fashion world; it's directional fashion, and it's a big deal for a celebrity like Reese to pick something like that."

Gardner was a bit surprised that Vanessa Hudgens, who was honored for having the "best hippie chic," and Kim Kardashian, who laid claim to the "best bikinis" in 2009, were among the top 10 best dressed. But Cruz commended both Hudgens and Kardashian for finding what works for them.

"We just thought [Hudgens] was really cute. She goes from hippie chic to rocker chic; she adds some edge with fierce accessories to off set her outfits," Cruz said.

As for Kardashian, Cruz credits her for doing the bikini with style. "The thing with bikinis is that you have to make them work with what you have, and she knows triangle tops and side-tie bottoms are what work for her body."

Rounding out the list are Nicole Richie for "best maternity," Taylor Swift for "best sparkle," "Slumdog Millionaire" actress Freida Pinto for "best use of color" and Cameron Diaz for "best jeans."

As any woman can tell you, jeans can be one of the hardest things to shop for, and the reason Diaz does it so well, Cruz said, is because she doesn't just stop at the denim. "Cameron favors skinny jeans, but one of the things that she does is that she accessorizes really well; she made the jeans look polished. She always added some pop of color to go with it."

Gardner agreed.

"Cameron Diaz, of all the people on this list, has the quirkiest style," she said. "Whether you're famous or not, you have to know what you like and know what flatters you, but still know that it's important to take chances. Reese took a chance with the Rodarte dress, and Cameron takes chances all the time."