Hey Mini, awesome cover song show! You said you needed some ideas I got a few:
Intelligent/Political type songs, this idea was used kinda, but we could use more intelligent/political songs, songs that speak on the world and or songs that with multiple listens, the listener gets something out of it.
Sountracks off of Superhero Movies, I am looking at the TDK soundtrack!
Motivational Songs, songs that can get you hyped up, or motivated to change the world!