Only Christian "band" I listen to currently is Pisces Dei, though they're actually a choir singing medieval Swedish songs. Not sure if they're still active, though.

Oh, and Handel's Messiah rules too!

My favourite Christian songs are: Personent Hodie, Ave Maria, Gladejlig, Behold the Lamb of God, Lacrimosa, and many others.

Other than these, I'm a big fan of Vox Vulagris and the Russian Red Army Choir.