Thai Kitchen is a little restaurant off of Trancas, just around the corner from where I live. There is nothing fancy or super unique about this place... except for, you know, the fact that I don't actually know of any other Thai restaurants in Napa Valley!
Unfortunately, restaurants that might be a dime a dozen in cities like San Francisco are actually pretty scarce here -- namely, I am thinking of Thai, Indian, Korean, German (heck, German food seems pretty hard to find practically anywhere), and others. There is plenty of Mexican, some French and Italian, California Cuisine and steakhouses, a few Chinese places, and an up-and-coming scene of sushi and seafood. However, this is the only Thai restaurant that I know of around here, and for some reason it's always very enticing whenever the weather is gray or raining.
The interior is typical but cozy, a little one-room/small-kitchen affair. The place seems to be family-run and they are always friendly and accommodating (today was actually my third time visiting). Although it's not fancy or unique, the place is never empty so that should say something. When I visited today, I overheard a conversation saying "This is surprisingly good... certainly way better than Sushi Mambo" (Sushi Mambo is a Japanese place in downtown Napa which I have never tried).
We ordered crab fried rice (very tasty, lots of crab meat, large portion to share for 2 people), duck pineapple red curry, and a vegetable/tofu noodle dish (Sarah's go-to dish, pretty good). All of the food I've tried there is pretty decent -- nothing I'd write home about, but satisfying in the same way that soul food is: fills you up and warms you to the core, so no wonder I'm always craving it on a rainy day. Or when we have a hankering for the orange, caffeine-boosted Thai iced tea... although we tend to save some money by making that ourselves at home now, using Pantai Norasingh mix ($5 per 1 lb. bag) which tastes just like what you get in the restaurants!
Verdict: Being one of very few (if not the only one) Thai restaurants around, this place is not bad for comfortable, casual food with a little kick.