Kim Anh is your best choice for Vietnamese subs on 17th Av. People often make the mistake of going across the street to Tai Tai for the same fare, but those people are missing out.
All of the items on the menu appear to be made by hand in-store (I've been there while they're hand-rolling spring rolls and boiling tapioca pearls.) and their Bubble tea selection is a good mix of sugary delights and fresh fruit/herbal mixtures.
The price is right and the service is quick - how can you go wrong?
The only reason I am docking them a star is due to no real place to sit and eat, you must take your food to go. In the summer they often put out some patio chairs out front for some nice people-watching, but that's about it!