Myself and my friends have eaten at Viet-anh's for years. After a day of shopping or appearing for an early lunch, hungover and bleary eyed.. You will always be greeted warmly and its perfect if you don't want yet another pub-lunch.
There are so many places around Camden that are overpriced and pretentious. If you want somewhere that has great food that isnt going to cost the earth then I really recommend it.
Viet-anh Cafe serve a variety of authentic Vietnamese dishes in a lively atmosphere.