Mrs. DrXmus and I have been dying to try Bahn Mi, but it just hasn't happened. One reason I haven't pushed it, too, is neither of us knows what to get and she doesn't eat beef/pork/scary items. What I'd like is to be told what to get. What suggestions do you Bahn Mi experts have for us?
I would get one with grilled pork (safe), and another with a paté (a bit more adventurous), split them, and see which direction the wind is blowing you in. They're so inexpensive that you can get 2-3 more to take home and try later.
Oops, I just saw that Mrs. DrXmus doesn't eat beef or pork. Try one with a variation of shrimp (shrimp paste, etc.), and maybe another with (grilled) mushroom, chicken, or tofu (or whatever they offer that appeals to you). The toppings on the sandwiches are remarkably consistent, from sandwich to sandwich, from shop to shop, so you'll have a good feel for what they taste like regardless of the main ingredient. I would recommend one warm and grilled, the other cold and paté-like, and split them to see what's up your alley.
Personally, I like something warm and grilled to complement the cool, sweet (from the marinade), crunchy vegetables.
Beware the jalapeño slice (it's not that hot, but it'll be there).
Just walk up to the counter, order by number (there will sometimes be pictures), ask them to cut the sandwiches in half (they often don't unless you ask), and pocket the change from your $10 bill. You'll probably have to ask them to wait a minute while you peruse the menu (they don't care).
Lastly, remember Jake Parrott's quote: "The only filling bahn mi, is a second bahn mi."