I like "Simply Thai" very much. Compared to other restaurants it is a little bit more expensive but the food it just delicious.
I have been to two Simply Thai restaurants, one is located in the shopping area of Xintiandi (North block Xintiandi, Lane 181 Taicang Lu, corner of Madang Lu and Xingye Lu) a beautiful restaurant, the other one is located in the French Concession close to the American and French consulate (5C, Dongping Lu).
As in many restaurants in china, all dishes you order a delivered to your table at the same time. That is okay for chinese food but not for other kitchens. I always tell the waiters to bring one by one. Works sometimes,