I guess the thing I like about Skillet is that they don't punch you in the face with their religion.... unless you watch their concerts on youtube. The thing I love about music is that you can get a message across without being overt about it. Hell, some of the most famous songs ever written were somewhat ambiguous. I think it's interesting how different people can interpret songs in different ways. So I think someone could write a Christian song, like "Hero", without it being obvious that the song is a Christian song.
I feel you. Some of Hillsong's stuff is like that, more metaphorical than literal. I think most artists go the other way with it specifically because they are making a point of not disguising their faith. But I could definitely see how groups could generate greater mainstream appeal by being much more subtle about their message. To each their own.
Christian music is generally rough (I say this as a Christian). If you like rap at all LeCrae, Andy Mineo, Propaganda, JGivens and a few others are doing some really good, non-cheesy stuff.
About the only form "Christian" music I enjoy is Christmas carols. But "spiritual" music has been around for generations. A couple bands/artists from my generation that I always felt were spiritual (and even "Christian") include the Moody Blues and Cat Stevens. Or maybe it was the drugs.....
You just had to remind me. You just couldn't help yourself. All these years later I'm still trying to sort out how the frick Jesus got to Broadway. Hangs me up to this day....