I haven't delved much into Vietnamese food since living here because most of the delicacies are soup or noodle based and it is quite hot here most of the year. We had a bit of a cool spell that nobody could explain so I went and got one of my favorite $2 meals that is available on basically every street in this country. It is called My Quang and it is wonderful
The price of this dish is as you would expect, more expensive in the tourist areas of town but I have also noticed that it is a larger portion and it seems to be "fancier" in these areas as well. The dish is a meat broth with thicker noodles than in the national dish called Pho and it is my understanding that Pho has become quite popular in the west as of late. My Quang on the other hand, I have never heard of it being available anywhere other than here.
You can order without hesitation because unless you desire it to be spicy, it has the spice level of a chicken noodle soup in the west meaning that it isn't spicy at all. Many people are afraid of ordering noodle dishes in Vietnam because Thailand, Cambodia, and a lot of Malaysian noodle dishes are much spicier than the normal western palate can handle but you needn't worry about that for most noodle dishes in this country. Vietnam doesn't seem to share the South East Asian flare for throwing loads of chilis into everything.
The dish is normally served with a bunch of random vegetables but bean sprouts seem to be the one consistent thing that is served at all of the places I have ever had it. It also normally comes with a few lime wedges and I recommend squeezing that into the bowl as well.
This other pic is unrelated to the noodles but was just a decent view across the street from where the shop was located.
You don't need to go to any particular shop to get a good My Quang as like I mentioned before this dish is VERY common in Vietnam and is available almost anywhere. I have been in the middle of nowhere and there was a noodle shop that sold only My Quang.
Eating Asian street food can be a bit of a challenge for a lot of visitors because they don't really know what they are getting themselves into but My Quang is a quite basic dish that can be made as exotic as you want it to be with the additives that are kept on the table. I would stay away from the large or small chilis though because at least for me those things can be a bit too much for the ol' mouth to handle! Enjoy!