The Curious Case of Benjamin Button is not the favorite in most of the pools to win the Oscar for Best Picture after losing at the Golden Globes and the Producers Guild and probably the PGA Baftar. Despite this the film has been more nominciones of this edition of the Oscars and I think it will be the winner. The Oscars are often not as predictable as many people believe and Slumdog Millonaire longer profile of winning a Golden Globe but not the Oscars.
Slumdog of Millonaire has already said it is the biggest favorite in all the pools so it would be no surprise that win, but I do not think it will, as I said.
Milk is discord in the third but I do not think you have no chance of winning any prize except for the important, not sure, best actor for Sean Penn, which for me is the most difficult of these Oscars.
Frost / Nixon is the last year's Juno, a film which has been cool and a surprise of the year but had to be nominated and recognized.
Reader is a movie you liked, but the Oscar options, I do not think you have options, where if you win it will be Kate Winslet for Best Actress.
Definitely The only options are Curious Case of Benjamin Button and Slumdog Millonaire and I think the film will be the winner David Fincher.