IT would be easy to label Sarah Michelle Gellar as just another pretty blonde. But besides the fact the Buffy star is naturally a brunette, she’s also a bright spark who is determined to challenge stereotypes.

“Being sexy is being confident,” she maintains. “Sometimes you meet people and they think ‘Oh, another cute little blonde actress’. That’s not who I am.”

But being petite and sexy and usually sporting honey-blonde hair will earn you lots of attention in Hollywood. There’s no doubt it helped the 30-year-old New Yorker into a successful small and big screen career, as Buffy The Vampire Slayer on television and Scooby Doo in the cinema.

But Sarah Michelle also proved herself to be a talented and edgy actress as the amoral centre of teen movie Cruel Intentions. Now, she is pushing the envelope again as a porn star in Donnie Darko creator Richard Kelly’s sprawling Armageddon countdown, Southland Tales, released on December 7.

Set in an America headed for disaster, the film charts a dizzying mishmash of interlocking conspiracies. It also stars Seann William Scott, and Dwayne ‘The Rock’ Johnson, as a clairvoyant paranoid schizophrenic. But rather than being put off by the oddness, Sarah Michelle embraced it.

“I play an adult film star who is also a reality television star, has an album out and her own soda drink,” she explains. “I actually signed up for the film before I read the script. Richard Kelly presented a world and an idea and a concept to me so thoroughly, I couldn’t say no.

“I had seen Donnie Darko and I thought this guy is so different and he has so much to say.”

She describes the film as a “dream come true”, although when it was first shown at the 2006 Cannes Film Festival in a rough form, there were jeers and walkouts.

After much re-editing and publicity spin, Southland Tales is now hitting screens across the world.

“I was so lucky because my character floated with the storyline so I probably got to work with the most amount of people,” says Sarah Michelle of her filming schedule. “I had such an amazing time on this film.”

Above all, she hopes it will make people stop and think. “That’s all I want them to do,” she admits. “The most important thing about art is to be evocative and make you re-examine things. Whether it makes you feel sad or angry or unhappy with the world, I want you to feel something and go home and talk about it.”

She also enjoyed filming the movie in Los Angeles, where she lives with husband Freddie Prinze Jr, whom she married in 2002.

“You’re walking your dog, you’re paying your bills and then ten minutes later you have to go to work,” she says. “I’m so grateful to actually film a movie in Hollywood, although some of the locations were pretty far.”

The couple try and ensure they aren’t working at the same time, a philosophy which recently led to her turning down the lead role in Stardust – it eventually went to Claire Danes – because it would have meant shooting in Britain and it was Freddie’s turn to film. Previously, she has also spent a lot of time away from home in Japan shooting The Grudge films.

“I turned Stardust down because it was Freddie’s turn in New York,” she adds. “I would have loved to have done it – are you kidding? But it was Freddie’s turn.”

Still, concentrating on the marriage and keeping it fresh is crucial, if only because she doesn’t ever want to have to go out on dates ever again.

“I’m so grateful I don’t have to go looking for a man on Saturday night,” she laughs. “I was always terrible at chatting up men.”

She is also one of the few young stars that rarely crop up in the tabloids and never for bad behaviour. “You don’t party when you’re on a TV show,” she maintains. “You learn your lines and you go to bed for 10 hours. I never smoked and I didn’t drink alcohol until I was 21.”

She puts her good girl demeanour down to a strong upbringing. Raised by her mother in New York, after her parents divorced when she was seven, Sarah Michelle credits the Professional Children’s High School with helping her through.

“You really had the chance to find yourself at that school. It was my lifeline.” Having being talent-spotted at an early age, she credits growing up as a child actress as a good preparation for fame.

In her teens, she was in the television series All My Children before landing the role of Buffy a decade ago.

Next up she depicts sorrow in the romantic drama The Air That I Breathe, will star in the film version of the book A Girl’s Guide To Hunting And Fishing – entitled Suburban Girl – and is down for the lead in the thriller Addicted.

Having managed to stay on the straight and narrow and juggle a busy career, she doesn’t have much sympathy for those that fail. “I don’t understand the need to give into excess and lead your life in public,” she says.

Still, she understands how emulating her lifestyle can be difficult. “I look at all these kids getting fame and attention now and they’re just not equipped to deal with it. In this day and age everything is so cross-marketed that the lines have blurred between actor and celebrity.”