I haven't heard the Blessed Unrest, so I can't judge its merit, but I'll go with RAM. I don't understand why people decided to hop on the Daft Punk bandwagon this era when they've had much stronger work. I'll never understand the Taylor love either, but she sells well so I understand the nomination. Kendrick should easily win, but he probably won't.
I feel like all of those albums don't really deserve a Grammy nominee, compared to other significant works such as 'Yeezus', 'Paradise', 'Pure Heroine', 'Unorthodox Jukebox', 'Nothing Was The Same'.