Love the Arcade Fire, Billie and Kacey albums.
All the others I've heard were good, but nowhere near the best of the year.
Of those, I'd disagree with Mumford and Sons the most... a hugely average (if not poor) album. Somehow beat Frank Ocean's Channel Orange as well
(other albums not nominated from 2011-12 include M83's Hurry Up We're Dreaming, Grimes' Visions, Fiona Apple's Idler Wheel, Florence + the Machine's Ceremonials, Drake's Take Care, Kate Bush's 50 Words for Snow, Purity Ring's Shrines...)