If you just want Bahn Mi, Lucy is the answer. I have had them all and I prefer Lucy.

For Vietnamese overall I can't honestly answer. I baby sat a Vietnamese kid for a while but his mom always insisted on making pizza and burgers for me, they were always terrible. So I never got as familiar with the more traditional dishes like I would have liked. Though that 3rd grader taught me how to use chop sticks like a fucking champ.