Let's first start off with the two sure things. One a four time nominee that has never won before and the other a previous winner that hasn't had the most stellar career post-win.
In a just world, Julianne Moore would by all accounts already be a two-time winner (for Boogie Nights and Far From Heaven), but the Academy passed her over in favor of others all the previous times she was nominated. And she hasn't even received a nomination (despite some traction for her work in The Kids Are All Right and A Single Man) since her double nominations of 2002, showing signs that perhaps the Academy had cooled in their affection for her. But after winning the Best Actress prize at Cannes for her go-for-broke performance in the messy/whackadoo Maps to the Stars (which will now receive a Oscar-qualifying run, but is way too out-there for be a serious contender), the buzz on Moore began. Then, almost out of nowhere, she became the front-runner for not only a nomination, but to win the whole damn thing with her film that debuted at the Toronto Film Festival, Still Alice. Moore plays a linguistics professors that finds she's in the early stages of Alzheimer's. Word out of the festival was stellar and it may be too soon to get our hopes up of finally being able to say Academy Award winner Julianne Moore, but a nomination seems pretty secured.
After reading the best-selling novel Gone Girl, I knew that whoever took on the part of Amy Dunne in the film adaptation would be sure to get some awards attention - the role is too juicy not to. Director David Fincher, after passing on bigger name stars, went with the relatively unknown Rosamund Pike, and, sure enough, Pike's star has risen and Oscar talk has begun. Pike, who has excelled in other films in supporting roles (her work as a not-as-dumb-as-she-seems blonde in An Education is a subtle delight), but I was lukewarm to her actual performance and to the film in general. But the film is already a huge hit and has inspired countless internet articles debating the notion of the "cool girl" and whether or not the film is misogynist. People are going to be talking about it for a long time and I think it'll be too big for the Academy not to include her in the Best Actress category.
The fifth spot seems to be a bit up in the air. There's two-time Oscar nominee Jessica Chastain for her work in the 80's set mob thriller A Most Violent Year. She could easily make the fifth spot as she also has the indie drama The Disappearance of Eleanor Rigby which has admirers and the sure-to-be-big Nolan blockbuster Interstellar out at the same time to raise her profile. Her best shot seems to be AMVY, but votes may split over her other films. Another outside possibility is Oscar-winner Marion Cotillard in Belgium's Best Foreign Language Film entry Two Days, One Night, which she is (once again) brilliant in. But for some reason, the Academy seems reluctant to give the actress a second nomination and this film may be too small and too foreign to make an impact.
Amy Adams Big Eyes
Felicity Jones The Theory of Everything
Julianne Moore Still Alice
Rosamund Pike Gone Girl
Reese Witherspoon Wild
My Favorite Best Actress Performances (of what I've seen so far this year)
Marion Cotillard The Immigrant
Marion Cotillard Two Days, One Night
Scarlett Johansson Under the Skin
Gugu Mbatha-Raw Belle
Mia Wasikowska Tracks