I'm not a fan of contemporary Christian music, but really dig some of the old-timey gospel and bluegrass Christian songs.
The documentary Awake, My Soul
has a companion soundtrack with two discs. One is recordings of really interesting Sacred Harp music and the other is a collection of modern artists doing Sacred Harp songs. I enjoy it on occasion, though the traditional shape-note style of singing takes some getting used to. You might enjoy the documentary regardless...I think you can get it from Netflix.
Johnny Cash recorded a few Christian albums. My favorites are My Mother's Hymn Book
and Hymns by Johnny Cash
The Carter Family also recorded quite a bit of Southern gospel...pretty much any of their albums will have at least a few Christian songs on them.
Lester Flatt, Earl Scruggs & The Foggy Mountain Boys recorded The Complete Mercury Sessions
a long time ago and at least eight or nine of the songs are gospel/bluegrass. The whole album is fantastic, if you like bluegrass, but the Christian songs are very beautiful in a down-home folksy way.
The Sacred Shakers are a Boston band (I think) that recorded a self-titled album of Christian songs and hymns that's really pleasant and upbeat.
The Rose Ensemble is a choral group with a more "churchy" sound; their main Christian album is called And Glory Shone Around
and has some absolutely gorgeous arrangements on it.
There's an album called Anthology of American Folk Music
in two volumes that has a ton of old songs from the 1930's on. The second volume is mostly gospel, some of it very good.
Let's see...that's all I can think of at the moment. I find most modern Christian music to be unbearably corny and/or not very Christian at all so I stick to the older stuff. Hope this helps.