For 1,500Vnd you can have a glass of Bia Hoi- Draught beer, which can vary in quality but is maybe the cheapest beer in the world. You also can order a grilled pork stick with a bread roll which could be your dinner. In the old quarter in Hanoi, there is one particular corner (Dinh Liet) where there are three bia hoi bars where heaps of backpackers and tourists hang around.
A bit further up the road, Bia Minh's is a good place for meeting friends with cold beer and you can see things happening down on the street from the second floor. It has a very friendly owner but don't ever order Bò Lúc Lắc, which is horrible.
The Maquis is my favortie bar in Hanoi which has the most friendly staff, good music, nice pictures, good cocktails, and the only bar using stubby holders for keeping cold beer. A small, late night bar with charactor and so popular with French people who live in Hanoi.
The popular backpacker bar now is Le Pub which is not very far from the lake in Hang Be street. Cold beer, friendly staff and art exhibitions for expat artists are the highlights here.
How about coffee? Cafe Năng, yes, only 5000Vnd that you can have a greatest coffee in Hanoi and sit right on the pavement watching all kinds of action going past.
Another popular bar is the Polite Pub, a nice place to catch up with friends, where there is a happy hour til 8pm. It has a friendly owner, really good, cold draught beer and good music that keeps me coming back.