Great place for the novice and also a solid choice for the veteran. For a Vietnamese food noob, the exterior and decor might appear a lil' shady. Inversely for the veteran, this is right up your alley.
The pho is always consistent, and the rice dishes are equally good. With a fairly good selection of pho joints in the area, Ben Thanh is definitely one of the better ones. Stop by if you're in the area.