I found this place right here on tripadvisor and it was a great choice. I paid US $35 for a nice room with queen size bed, flat screen TV, good hot water, well stocked bathroom and refrigerator. A/C could be better. Breakfast is OK, internet is free in the basement and staff is excellent and very helpful. They'll be happy to sell you tours, but won't bother you about it. The neighborhood is good, close enough to the lake and all the sites, plenty of shops and restaurants and a good bakery next door, but a bit removed from some of the most chaotic parts of old Hanoi, which is good.