I am a big fan of Nana and have eaten there a number of times. The restaurant is small and the vibe is loud which I enjoy. I have samples a few different dishes on the menu but always seem to end up getting the Khao Soi and adding a little bit of roasted chilli to bump up the spice level.
The Khao Soi is the perfect amount of food for me, but some of the other dishes are a little smaller. I would suggest getting an appetizer to share if you are very hungry.