First bit of advice is to check ReidOn. The author is a Lonely Planet writer and knows his stuff. We didn’t get around to all his tips but we can certainly vouch for some. The SavourAsia page is also very helpful.
1. Quan An Ngon is a must. Especially if you are in Hanoi for a short time you will want to try as many different “street food” dishes as possible and that is only possible at this concept restaurant. Basically they took a bunch of “food stalls” and put them in the courtyard of a beautiful colonial mansion. The food is great, atmosphere is stunning, and the prices are actually not much more than what you would pay on the street. The quality here is often better too, not to mention the hygeine. SavourAsia has a brief description of where/what it is.
2. Highway 4 turned out to be my favorite place in Hanoi. Read Reid’s review here. The Old Quarter location is the one we went to and loved it. The rice wines can be sampled for .50 to $1.00 per shot and some of them are tasty. The food is quality fun, we tried a lot: the catfish rolls, the cricket rolls, and the fried locusts with lemongrass (great beer snack). The 8 types of mushroom and anything else you order will be good too.
3. If you’re up for a splurge, and happen to be around on a Friday night, there is an expat joint called Brothers. Brothers has a solid seafood buffet including free-flow wine (the wine was Argentinian when we were there) $20/pp. Pricey for Hanoi but we bit the bullet and were happy–you can get all manner of briny creatures grilled before your eyes. Had the best grilled anchovies I’ve ever had and this is coming from someone who just spent 7 weeks in Turkey where all they eat are fresh anchovies!
4. Street food is fun and cheap but we were very disappointed with the lack of visual displays and lack of variety. Also, places have spotty hours. You really have to know where to go and when. Most vendors are honest but some will rip off foreigners. One reliable joint for us was eel soup at DONG THINH MIEN CUON address: 83 Hang Dieu St, open all day and into the night, too. The main thing they serve is soup with cellophane noodles and fried eels but they also make a decent eel congee (called chao in Vietnamese). We ate here 5 or 6 times at least.
5. I don’t care much for pho, but if you do then supposedly the best is PHO GIA TRUYEN on 49 Bat Dan St. They open at 6AM and are usually done by 9, 10 AM latest. Sometimes they reopen at night but I wouldn’t count on it. Josh said the pho in Vancouver was better, which accounts for the fact that northern Vietnamese pho uses a clear broth whereas southern pho is richer and more filled with the characteristic ingredients (tendons, lots of herbs, etc).
6. I’d call this a “must” if you have the time: CAFÉ PHO CO. Better known as “Secret Coffee” because it’s hard to find. The entryway is behind a store, and the store is at 11 Hang Gai St. Just walk through the store and then you will see a lovely Asian courtyard. A lady will hand you the menu, you place your order and then go up 3 flights of stairs. When you reach the rooftop you will get the best view of Hanoi and Lake Hoam Kiem.
Honorable mentions: Cafe Stop and Luna d’Autumno for Western food. You’re traveling long enough that you might want some Euro eats and these are both decent (but different). Cafe Stop is owned by a French expat and it’s a great place for omelet. Has a coffee shop atmosphere, and is not expensive. Luna d’Autumno is full-on Italian and very good quality. Pastas are all made in-house. I had an extraordinary ravioli stuffed with eggplant and walnuts with sage butter sauce. Good wines. Prices are a little less than what you would pay at home.
1. We visited 11 of Hanoi’s brewpubs and there are still more. The brewpubs exist for Vietnamese, not expats or tourists (surprisingly). Hanoians like beer! If you aren’t as into beer as we are, Legends is the easiest one to visit and it’s in all the guidebooks. The beer isn’t great but it’s not bad either. The view from the outdoor patio is excellent, as good as the “Secret” coffee I told you about. It’s an even better place for gawking at the traffic.
2. If you like Czech beer, I would strongly recommend Hoa Vien brewery. It’s not that far out of the Old Town and has a great atmosphere and the best beers in town. Their food is good too, I could have put it in the restaurant list.
3. Highway 4 (mentioned above) for the rice wine. Don’t know much about these rice wines. The ones at Highway 4 are made by one manufacturer/distiller. Some of them are mild, some are potent, and most are tasty. The best ones are complex and herbal.
4. Bia hoi! If you don’t know what bia hoi is, then you will as soon as you plan a visit to Hanoi. It literally means “fresh beer.” It’s a communist principle: beer for the masses produced in large quantities and costs so little that everyone can afford it. Each glass is 3000-6000 dong (10-30 cents) depending on where you drink it. The quality of the beer matches the price but it’s more about the experience. All bia hoi is drank on the sidewalk in the child-sized plastic chairs. There are lots of bia hoi vendors but if you feel like meeting other travelers or being in a bustling environment, then you must go to Bia Hoi corner. It’s a corner of the Old Quarter with 3 bia hoi vendors that have attracted a loyal backpacker crowd but some locals drink there too. Bia Hoi corner is a unique experience, memorable, and quintessentially Hanoian. If you feel like a more Vietnamese crowd then there are lots of places you can go around town, just look for the signs and pick a spot.
5. If you really love beer and are dying for a quality quaff, then My Way is the way to go. They have a solid list of Belgians including Trappist ales. They use proper glassware, store and serve their beer properly. They have a number of different locations, the one across from the Opera House has a great atmosphere and view. If you are staying near Opera House that would be the one you check out. Prices are what you would pay at home.