I have always enjoyed this charming little restaurant just off Sukhmvit. I can't remember the exact address but if you get off at the Ambassador hotel from your taxi and walk past the outdoor bar as if you are walking away from the hotel then it is right across the road from the bar. Very good food in a nice setting. You Don't feel as if you are in the middle of Bangkok.
Very traditional Thai restaurant. Good if you are on your own and need a central place to eat.