A Hollens Family Christmas by Peter Hollens and Simply Christmas by Leslie Odom, Jr. were pleasant surprises.
Other songs that are simple and beautiful: Sarah Brightman's "Silent Night" (Winter Symphony album), Julie Andrew's entire album devoted to songs about the Christ Child, and Bocelli's "Cantique de Noël." The acapella group Straight, No Chaser is generally rambunctious, but I enjoy their modest renditions of "Sweet Little Jesus Boy" and "Hark the Herald Angels Sing."
I got a kick out of an album called Christmas at Downton Abbey, partly because some of the songs were awful (but were thought acceptable since they were sung by people in the cast), but partly because one of the actors (Julian Ovenden) really can sing. Who knew? Some of the choral pieces done by the Choir of Kings College were quite beautiful and Jim Carter reading "The Night Before Christmas" is a real treat.
I'd love further suggestions for meditative and acoustic Christmas albums.