While we're dipping into Christian rock of the 90s, I'd like to second the motion on Sixpence None The Richer and Jars of Clay. Those are both bands that have put out work of real artistic integrity.
The Jars of Clay albums that most impress me are If I Left The Zoo and Who We Are Instead. All their work has something to commend it, but I think these two albums have the most consistant quality of material.
Sixpence None The Richer's Divine Discontent ranks with me as one of the great underrated albums of all time. It's brilliant from beginning to end (with the possible exception of an ill-chosen cover tune, Crowded House's "Don't Dream It's Over"--no problem that they covered it, but they added nothing of substance to it in doing so).
Also there is a little-known duo from Nashville, a husband-and-wife team known as Flemming and John, who did a couple of astounding albums, and had a minor hit on the pop charts with a hilarious tune called "Ugly Girl" which is a big favorite of mine.