PLACES TO VISIT IN EAST INDIA

I'm going back to India for a 3 week vacation next month after living in Delhi for 6 months in 2010. I'll be traveling up the east coast from Bangalore to Sikkim with a few friends, primarily by train. Where should we stop?? All food/beach/trek/lodging recommendations welcome.
  1. Here's the general itinerary:
  2. And some places we're currently planning to stop along the way:
  3. Bangalore
  4. Tirupati
  5. Visakhapatnam
  6. Araku
  7. Orissa beaches
  8. Kolkata
  9. Darjeeling
  10. Sikkim
  11. Halp!