The problems with the thai restaurants I've visited in Seoul are either they're good, but really expensive, reasonably priced but either not flavorful enough, or flavorful, but too spicy.

Thai Orchid is the place I've found so far that balances all those, with good flavors, spicy enough to enjoy, but not so much to overwhelm the flavor, and all that for less than 25 000 per person. The Tom Kha Gai - coconut milk soup - is my favorite on the menu. The decoration is a little plain - the unfinished ceiling is still visible, but the colored cloth drapes do a good job of filling in the space. Regardless, the food is great, and the service was satisfactory.

There is a private room to one side of the restaurant.