Thai or Japanese fusion restaurants are quite in fashion these days- one could name dozens of them on both coasts of the Atlantic. Unless you are in Thailand though, really authentic Thai restaurants are not that common.
Le Banyan (24, place Etienne Pernet, 75015, tel 01 40 60 09 31) is an exceptional Thai I recently found in Paris.
What I like about Le Banyan is the authenticity of flavours and the beauty of the dishes what you will not find anywhere in Paris. They say, that Thai cuisine for Asia is the same as French cuisine for Europe. And indeed, when I was in Thailand few years ago, I was impressed how beautiful and elaborated their dishes are.
From the first sight, Le Banyan looks more like a trattoria or a “take a way” eatery than an “haute gastronomie” restaurant. But when you see and taste their dishes, you really feel like in Thailand!