Charlize Theron debuted her new movie 'Battle in Seattle' in New York City Wednesday night, and she had nothing but praise for the project -- the directing debut of her live-in steady, Stuart Townsend!

"This is a great night for him," Charlize tells ET, admiring Stuart's passion for the project. "This took like five or six years of his life."

As for joining the project, Charlize admits, "I didn't want to come across too desperate, so I tried to be subtle to [land my part]."

Just named one of People's 10 Best-Dressed Stars of 2008, Charlize looked stunning in a ruby red Dior dress, but was very down to earth about having some days where you want to "hide," where other times you "feel like you're a princess." As for Stuart's wardrobe choices, she offers, "It's really nice to be with someone who has a great sense of style himself."

"She's been by my side the whole way through," said Stuart of his live-in girlfriend. Of his indie movie that "was like a military operation," he added, "It took some time to work this story out. So she stuck with me through it."

Featuring an all-star cast that includes Woody Harrelson, Ray Liotta, Andre Benjamin, Connie Nielsen, Joshua Jackson, Channing Tatum and Michelle Rodriguez, 'Battle in Seattle' chronicles the true-life turbulence that occurred when demonstrators against the World Trade Organization clashed with the government and the National Guard on the streets of Seattle for five days in 1999.

"I think it's important to raise awareness about [the WTO]," Rodriguez tells ET.

'Battle in Seattle' opens in limited release this Friday.