For supporting actor, my preferred list in descending order:
Jared Leto, "Dallas Buyers Club"
Michael Fassbender, "12 Years a Slave"
Barkhad Abdi, "Captain Phillips"
Bradley Cooper, "American Hustle"
Jonah Hill, "The Wolf of Wall Street"
I mentioned about Judi Dench that she simply is in "Philomena," fully occupying her character without acterly flourish. The same can be said of Leto, who years after serenely inhabiting Jordan Catalano, does the same in "Dallas Buyers." And that is why he deserves the Oscar. But, again, I have gone back and forth some on this list, at least where the runner-up is concerned: Fassbender might be accused of hamminess until you look past his character's excesses to see how real Fassbender makes them, and he is one of those actors whose body of work calls for an Oscar, especially in his collaborations with Steve McQueen.
Abdi takes over large parts of hisvie -- only we don't know yet if this is an out-of-nowhere miracle performance that works because we have no movie history with him, and he may never have such a role again. So Fassbender and Abdi are 2/3 or 3/2 depending on how I am feeling in the moment.
Cooper's a good enough actor, but this is not his best performance, and he's a step behind the three above. Same thing with Hill, and we've seen him play needy jerks before.
Best supporting actress:
Lupita Nyong'o, "12 Years a Slave"
June Squibb, "Nebraska"
Julia Roberts, "August: Osage County"
Jennifer Lawrence, "American Hustle"
Sally Hawkins, "Blue Jasmine"
To see how much Nyong'o brings to this role, and how revealing it is of her skills, check out "Non-Stop," where she is given almost nothing and is possibly the least memorable character in it. In "12 Years," she is the tragic companion to Northup's story, doomed to abuse and dehumanization even as he escapes. June Squibb, in comparison, has miles of credits but, like Nyong'o, got a role that let her show how considerable her acting can be. I would not complain a bit if Squibb won. Roberts gives one of her better performances, but she's not a supporting actress in "August"; she's one of the leads, and should have had to fight Streep et al. for a nod in that category. Lawrence is adorable and charismatic, and a fine actress, but she's not the best here -- even if she wins. Hawkins is a baffling fifth choice, especially when Oprah Winfrey's tremendous work in "The Butler" was not nominated.