Here in Fremont, it seems every other storefront is a Thai restaurant. (They alternate with the coffeehouses and antique/junk shops). But among them, Kwanjai stands out for its friendly and blindingly fast service, reasonable prices and, especially, its truly outstanding food.
The noodle dishes, especially the Pud Kee Mao, are fresh and flavorful, and they really will vary the "heat" of the dish from very mild to painful at your request. The curries, especially the green curry, are plentiful and delicious. And the entrees, such as Summer Fire, have great fresh vegetables. Everything's good with tofu or meat.
The waitstaff are friendly and helpful, and the service is unbelievably fast, even with a group of four. In the summer, there's outdoor seating; highly recommended, since the restaurant gets pretty hot.
I can't recommend this place enough; it's an absolute gem.