I'm usually a fan of metal and rock (what with one of my all-time favorite bands being Metallica and all), but when I'm in the mood, I'll listen to rap like good 'ol Snoop Dogg, maybe a little Nas or Eminem.
If I'm craving rock but on the softer side, I'll listen to Counting Crows, Coldplay, Creed or maybe even Nickelback.
One thing I'm totally not ashamed of listening to when not listening to metal? Royksopp. Melody A.M. is one of the best albums I've ever listened to. I love how relaxed they sound.