Hopefully:
Waitress (OBC), She Loves Me (ORC), The Color Purple (ORC), School of Rock (OBC), and Bright Star (OBC).
I think the competition is between She Loves Me and Waitress. I don't understand the hate for Waitress. I think it sounds great. It just sounds a bit more poppy then the usual cast album, but I'm ok with that.
However, She Loves Me is probably one of the best cast recordings of the last few years. The cast is fantastic, the orchestra shimmers, and it has some of the best sound quality that I've heard on a cast album in years. What makes this album perfect for me though, is that I can close my eyes and see the show in my head when I listen to it. That for me is the secret to what makes a great cast album. Some of the other albums have been soooo processed that no emotion or performance comes out in the music (I'm looking at you Color Purple). Sometimes I think they're more concerned about singing perfectly than giving a whole performance.
Who I think should win: She Loves Me