The only thing I don't like about this place is that there is always a line. I would take a star away for not taking reservations, but I like everything else too much.
Living just around the corner, I average eating at Khao San Road about once every two weeks. It's just about the best Thai in the city, and the cool ambiance and location take it to the next level. No kitschy decor choices or dinginess - just a clean, modern palette that lets the food speak for itself.
And the food sings! You will find all the traditional Thai selections here but there are a couple of standout dishes. The Khao Soi is marvelous medium-spicy, the Massaman curry is the best I've ever had, and I've heard the Pad Thai is equally as good (not being a fan of the dish myself). To start off, you can't go wrong with the fresh rolls, squash fritters or daily soup.
If only they would expand into the neighbouring space and eliminate the lineups, it would be perfection!