Spotless Pho Vang is a great alternative to heavy German fare, delivering authentic Vietnamese pho (noodle soup) and other traditional dishes that aren't altered too drastically to suit the European palate (excepting perhaps a popular crumbed chicken dish that's probably not often seen on the streets of Hanoi). It's cheap and delicious, with plenty of options for vegetarians.
Pho Vang
Top choice in Fairy-Tale Road