Christina Applegate Tops PEOPLE's Most Beautiful 2009

She has an "angel" of a boyfriend, Dutch bass player Martyn Lenoble, "who loves me from head to toe." She has a cozy Malibu beach house that she calls "the best thing I've ever done for myself." And, after a very public battle with breast cancer that has given her a gratifying "feeling of purpose," Christina Applegate has a new lease on life, she tells PEOPLE.

[ Take a Peek at the Most Beautiful People of 2009! ]

"I used to be really shy but I started to come into my own in my late 20s and early 30s," Applegate, 37, says in the cover interview for the annual Most Beautiful issue -- her first interview since her reconstructive breast surgery last November. "Now I'm not afraid to speak up in a room full of people and be a part of the conversation."

"You have to get through the physical transformations," continues the "Samantha Who?" star, who underwent a double mastectomy in July, "then buck up, go to work and try to be the normal, happy Christina for everyone around you."

[ Check out Christina's FIRST 'Most Beautiful' spread from 1999! ]

Applegate is joined on PEOPLE's Most Beautiful list by newcomer Robert Pattinson, Kristen Stewart, Dev Patel, Selena Gomez, Channing Tatum, and Natalie Morales.

Appearing in PEOPLE's "Stars Without Makeup" section are Eva Mendes and Cindy Crawford, who tells the magazine, "10 years ago it would have been harder for me to do this picture ... I'm just more comfortable with myself now."

[ See Other Stars Most Beautiful Moments ]

Also in this section, which is made up of celebs who wore nothing more than moisturizer for their close-ups, are the girls of "90210" (Jessica Stroup, Annalynne McCord, Jessica Lowndes, and Shenae Grimes), Claire Danes, Ciara, Amanda Bynes, "Idol" judge Kara DioGuardi, and "Terminator: Salvation's" Moon Bloodgood.

President Barack Obama and other head-turning members of his inner circle are also represented in this special issue. First Lady Michelle Obama tells PEOPLE, "I had a father and a brother who thought I was beautiful, and they made me feel that way every single day. I grew up with very strong male role models who thought I was smart and fast and funny, so I heard that a lot. I know that there are many young girls who don't hear it. But I was fortunate..."

Cover girl Christina Applegate credits her own personal reservoir of strength -- her boyfriend. "He's been a friend for about 13 years," she says of Martyn Lenoble. "Our relationship gets stronger and stronger. I'm really lucky." And, more importantly, he makes the actress feel "beautiful" about her new body. "I'm very grateful to Martyn for coming along at a time that he did because he's been my rock through all of this, Applegate shares. "He gave me something to really want to live for and something to smile about."

And speaking of smiles, the new issue's "Love That Smile" section features Jennifer Lopez, Angelina Jolie, Brad Pitt, Hugh Jackman, Matthew McConaughey, Jennifer Garner, and Halle Berry.