I don't have much experience with Thai food, so when someone asks me for a pairing reccomendation, I usually go the safe route and suggest a Riesling. When I read this article about "bucking the trends" when pairing wine and Thai food, I found it really interesting. It discusses traditional ingredients in Thai food, and why it can be hard to pick a wine to accompany it.

From the San Fransisco Chronicle:

The far greater problem with pairing wine with Thai food isn't heat, but the crippling effect of too much sugar. Too many Thai restaurants in the United States smother their dishes to accommodate the American sweet tooth.

It used to be that a touch of sweetness toned down the burn of the chile. But now overwhelming sweetness is the norm. Sugar can drown great wines because a good pairing usually requires the wine to be sweeter than the food (and is why wedding cake and Champagne clash like feuding uncles).

A degree of sweetness is essential, which explains why off-dry Rieslings are a near-perfect solution for most Thai dishes. But it's important to keep sweetness in check for both wine and food, or risk losing the nuances in both.

The article also has extensive food and wine pairing suggestions. Here is one of them:

Sweet and sour
One of the most popular flavor combinations in Thai food largely borrows from Chinese tradition. In both food and wine, you need a balance of sweet and acid. Red wines can work, so long as they have a minimum of tannins.

Food: Pad Thai, northern Thai pork curry, tofu tod (deep-fried tofu with sweet-and-sour dip)

Wine: You want high sugar, high acid and a high level of fruit extract - dense, sweet and tart. Hence Riesling is the undisputed winner here, as are Scheurebe, Pinot Gris and other aromatic white wines, the sweetness level matched to the dish. Zinfandel is a good pick among reds, with its lingering sweetness - though be mindful of alcohol levels. Balanced Pinot Noir with just a hint of sweetness can work, too.

Be sure to head over there for the rest if you enjoy Thai food. I found it really helpful!