Tiny Thai restaurant at the Lang farm center in Essex, VT. is fantastic. Much better than the Burlington based Thai restaurants such as Parima, Loong Chat (terrible) and Bangkok Bistro (paeng maak...too expensive and not that great). My wife is Thai and she was a bit jaded after disappointment with all the Burlington area Thai establishments. After living in Bangkok for a year, I agreed with her that they were too "Americanized".
I decided to try Tiny Thai one day and was pleasantly surprised. Their Pad Thai is actually better than some I had in Bangkok just a few months ago.
In defense of all "real" Thai restaurants, they do their best to stick with authentic Thai ingredients but some of the spices and veggies are just too expensive or would spoil while being imported here. Then there are the others who just call themselves Thai (the absolute worst being that newly opened Thai take-out at University Mall) and serve up a bunch of noodles with some kind of canned sauce or load it up with American veggies (Loong Chats) to make it look like you're getting a lot of food.
The other excellent Thai restaurant is the Royal Orchid in Montpelier. Don't care much for the owner but I have to give the devil his due...food is excellent and totally Thai. There's Thai Basil in Stowe which is an unbelievably expensive establishment with mediocre food. Go with Tiny Thai or Royal Orchid, skip the others.