Pandit Ravishankar's Vedic Chants of India never fails to relax me when I am mentally exhausted.
Simple every day chants set to soothing music be it the Gayathri Mantra or Asathoma. Brings tranquility to mind in troubled times. :)
Here is Sarve Bhavanthu Sukhinaha :
Here is the entire set : http://www.rhapsody.com/ravi-shankar/chants-of-india