Jennifer Aniston stepped out in style Saturday night as she and fiance Justin Theroux attended the 2012 Art + Film Gala honoring Ed Ruscha and Stanley Kubrick in Los Angeles.

Aniston opted for a revealing black Tom Ford gown, which was extremely low cut and showed off ample cleavage. Her primary accessory was the enormous engagement ring Theroux gave her when he popped the question in August, which includes a giant diamond and has been valued at about $500,000.

The event, held at the Los Angeles County Museum of Art, drew a host of A-list guests. Aniston was spotted catching up with celebrity pals including Salma Hayek, Cameron Diaz, Ellen Barkin and Joan Collins.

CLICK HERE to check out a series of photos of Jennifer Aniston, Justin Theroux and a slew of celebrity friends at the Art + Film Gala hosted by the Los Angeles County Museum of Art.

An insider who attended the gala told Us Magazine that Aniston accented her engagement ring with a bridal-inspired French manicure.

"Her ring is huge," the source told the magazine.

The Art + Film gala was only the most recent in a string of high-profile appearances for Aniston that offered her the opportunity to show off her huge rock.

She attended the annual Vogue CFDA Fashion Fund event last week at Los Angeles' Chateau Marmont hotel, where she rubbed elbows with other A-list attendees including Vogue editor Anna Wintour, Gwen Stefani, Katy Perry, January Jones, Tobey Maguire and his wife Jennifer Meyer

CLICK HERE to check out a series of photos of Jennifer Aniston and her engagement ring from Justin Theroux at a soiree for the Vogue CFDA Fashion Fund.

The actress, who is known for her simplistically chic and laid-back style, recently admitted that to her, the most important part of fashion is comfort.

"Don't wear jeans that are so tight they make your tummy hurt. Don't wear heels that are so high you feel like you're going to fall over," Aniston said. "Sexy is about being at ease with your body.