I know this might be weird, because I'm primarily a metalhead, but I've started to love underground rap/hip-hop. R.A. The Rugged Man, Jedi Mind Tricks, Army of the Pharaohs, Reef The Lost Cauze, Immortal Technique, DJ Shadow, Deltron 3030, Celph-Titled, and a few more. I used to always say "Rap/Hip-Hop's lame, no talent" like a lot of other people, but then I started listening to underground stuff, and I really love it. The beat's awesome, and all of the songs have quite a bit of depth to them, rather than "I get mo girls den you get yoooo" like what most mainstream crap is. I highly recommend Uncommon Valor: A Vietnam Story by Jedi Mind Tricks, featuring R.A. The Rugged Man. Make sure you wait for R.A.'s part, it's simply the best moment in hip-hop ever