In 15 years in Thailand i have traveled around about half of the country Whenever i have come across a restaurant that serves western food, i have tried their fish and chips if they are on the menu, as i like fish. I have not been too impressed with most of the fish and chips i have tried and cannot remember some of the earlier ones that were OK.
However since being introduced to the "Swan Bar & Restaurant" in ( Buriram that i frequent once a month for my shopping), i have to say that their fish and chips, English style is definitely the best i have tasted in Thailand.
Just my opinion but if you are traveling through Buriram, give it a try and see what you think.
Their breakfast by the way, is huge and will keep you fueled up for the whole day.