Silence is only open on a very small handful of screens right now. But I've heard nothing but good things. That seems like the main competitor, but not enough people have seen it yet for me to get a handle on the consensus.
Arrival will probably get nominated, and I would be happy for it if it won I don't think it will. It's a great movie but Villeneuve has done better in the past and will probably do better in the future.
Moonlight I am curious to see, but it didn't play at my local theater and is already out of theaters at the other theaters nearby. So I'll have to wait a while longer to see it.