I am a big believer in the idea that art is bigger than just the intention of the person who created it. Some of the songs that make me feel closest to God and describe my relationship with him best were clearly not intended as worship songs, either because they're part of a broader context (like a musical) or because they're written by people who aren't Christians at all. But if a song connects me to God, it connects me to God, whether or not the writer ever intended that.
So these are some of my favorite songs to use for worship that you'd probably never hear in a church service.
And my all-time favorite: