I remember trying out the Bo La Lot in HCM city and is a great dish. It is not as popular and well known as the Pho Bo but I think is a must try dish if happen to be in the city. It is the Vietnam Betel Wrap Beef grilled in charcoal fire. Comes with salad, rice paper and a peanut dipping sauce. The combination of the Betel leaf, mince beef, lettuce row, is just wonderful. Not many places have the dish but you can find it somewhere or ask around. Also you can check out my blog to see what is it and get more information.
http://sensesofvietnam.blogspot.com/