Schmer, I completely overlooked Monica Bellucci in
Malena, she would have had a good shot at making my list.
Surprisingly, this category was the only one I was able to fill out almost off the top of my head, and I can stand behind my choices here more than in a few other categories (I may have made a couple of questionable late-night decisions)
My list:
Abbie Cornish Bright Star
Anamaria Marinca - 4 Months, 3 Weeks and 2 Days
Ellen Burstyn Requiem for a Dream
Imelda Staunton - Vera Drake
Isabelle Huppert The Piano Teacher
Julia Roberts Erin Brockovich
Julianne Moore - Far From Heaven
Kate Winslet - Eternal Sunshine Of The Spotless Mind
Kate Winslet Little Children
Laura Dern Inland Empire
Maggie Cheung - In The Mood For Love
Maria Bello - A History Of Violence
Naomi Watts Mulholland Drive
Nicole Kidman Dogville
Penelope Cruz Volver
Q'orianka Kilcher - The New World
Sally Hawkins Happy-Go-Lucky
Samantha Morton - Morvern Callar
Samantha Morton In America
Sissy Spacek In the Bedroom