Muzaffarpur Experience: Its wonderful, much better than all tourist places in India. Even after ignorance by tourism department, it still beautiful.
You must visit Chamoonda Sthan and Pahsaul (40kms far from city towards North East) if you want to feel heaven.
Food, sight-seeing and shopping: Indraprastha Colony
Activities & things to do: Visit on Rikshaw
Travel tips, How to reach, travel warnings etc: Be careful all the time