Great restaurants in Hanoi?

Cha Ca La Vong is certainly an iconic place in Hanoi, and Koto Restaurant is a cool concept. Personally, though, I don't much see the point in proper restaurants in Hanoi. You will literally be tripping over some of the world's best street food. If you really want to dig into specific locations for street food, start reading the blog Stickyrice (http://www.stickyrice.typepad.com/). But take my advice with a grain of salt—I prefer a gutter-side grill to white linen and stemware. :) I think you'll eat well in Vietnam no matter what you do (as long as it doesn't involve a hotel buffet)!

I must say: Koto Restaurant , Hoa Sữa, Bun Cha Dac Kim in Hang Than str & one restaurant at 72 Ma May str where a number of tourists gather (good food, nice atmosphere & reasonably priced)

In the Old Quarter, some of the streets are named after the things sold on them. That includes fun. Look for any place there that specializes in bun cha ha noi. That stuff is delicious.

We tried this restaurant in HCMC, but they also have a location in Hanoi:  Nhà Hàng Ngon.  The owner took the best street food vendors and put them under one roof.  You order from a standard menu, then the food is cooked at the various different vendor's stations and brought to you!  Brilliant, and yummy.

We did eat at Koto Restaurant.  The name is short for Know One, Teach One.  The owner employs very poor and underprivaleged youth to help them gain knowledge of the hospitality industry and provide opportunity for the long term.  The food was excellent, staff was lovely and the location is right across from the Temple of Literature. Try to sit upstairs near the windows.