It's about time I gave this fish and shop shop in Bangkok a plug on here. I have been using it regularly for years, and I can safely say it serves up great fish and chips ! You can find it just down Sukhumvit Soi 23 on the left hand side of the road, before you get to Soi Cowboy. The staff are friendly, the food good, and prices are very reasonable. Its a great stopping off point on the way home after a night out.
Before you ask, you can get cod ! Of course its more expensive than the local fish but its worth it for the taste. You can eat in or takeaway. The owner of the shop has the bar nextdoor as well, so beer and stuff is available too !
In fact I went in there last night after a few beers and shots in Tilac Bar ( now the best bar in Soi Cowboy in my opinion ) and somehow managed to order my usual egg and chips. Or perhaps I didn't order it and they just gave it to me as its what I usually order ! I can't remember !
Anyway, if you are in Bangkok make sure you visit the place. Take it as you find it and enjoy !