Blue monkey is not authentic and over priced. Hua Thai is the BEST and resonably prices thai food in Zurich. Small casual and need reservations if you go during normal dinner/lunch hours. Here is the info:
Hua Thai
Hardstrasse 320
Tel 044 271 54 30
The other GREAT thai food is in Neiderdorf, new Munster church called Bon Song Thai, here is the link.
www.bansongthai.ch
Cheers...