Pretty Woman: InStyle’s September Cover Star Julia Roberts on Her Best Red Carpet Looks

Roberts made a gender-bending style statement at the 1990 Golden Globes when she arrived in an oversized Giorgio Armani suit, which she picked up off the rack at the store. "I loved the shape of it," she said. "For me, this was the epitome of being dressed up."

At the 51st Annual Emmy Awards, the front of Roberts's black fitted gown looked covered up, but the back incited oohs and aahs. "The dress was backless," she said. "Actually, it wasn't a whole lot of dress."

The actress looked elegant as ever at the 2001 Golden Globes in a long-sleeve Armani sheath. "It's simple and beautiful," she said. "I love those dresses that you put on and there's no fussing with it."

Later that same year, Roberts stunned audiences at the 73rd Annual Academy Awards in a floor-length, black and white Valentino gown. "The Saturday before the show, I had lots of options but still didn't know what I was going to wear," she said. "The stylist pulled this out and said, 'I found this in the vault at Valentino and thought you'd like it.' I think it had been worn only once, nine years earlier, and they'd stored it away. It fit me perfectly." That same evening, Roberts took home a best actress statue for her role in Erin Brockovich.

At the 76th Annual Academy Awards, the actress donned yet another figure-flattering Giorgio Armani number, which she co-designed with the man himself. "People thought it was a 50-bazillion-dollar diamond brooch, but it was just a little costume pin!" she said.

Roberts opted for a pop of color at the August: Osage County première at the 2013 Toronto Film Festival. "That was a really fun night," she said. "I've always loved Dolce & Gabbana because they make things that you zip up and go, 'Done!'"

The actress wowed in another DampG frock, which she made her own by adding another layer on top. "I didn't know if I'd feel comfortable in the dress alone—I felt super-naked," she said. "My stylist, Elizabeth Stewart, knows I love tuxedo looks, so she smartly suggested we tailor a white shirt to wear under it. And it worked!"