I pondered this as I was listening to a Megadeth song in the car yesterday.. his songs have some great deep lyrics about various issues that make you think.. they're not just carbon copy songs about women and relationships. My favorite album is probably the "youthanasia" album. https://www.youtube.com/watch?v=e7HA3zPrQso

Also "countdown to extinction" and "hangar 18"

Do you have any favorite bands that have deeper content to their lyrics?