Korean is perhaps the safest bet, for two reasons. First, non-Koreans are not usually interested in the food. They might enjoy Bul-Gogi but there will be plenty of other dishes for Korean patrons and these will not be "dumbed down." The lack of mainstream interest limits the potential for sell-out behavior on the part of the restaurant. Second, many Korean dishes, most of all the pickled vegetables, "travel" relatively well and do fine in a culture -- the USA -- which is not obsessed with fresh ingredients.
Which cuisine are you most likely to be satisfied with when dining out? Which disappoints you the least # of visits?
If you were at a shopping center you've never been to before and it has one restaurant of each cuisine and your goal was to simply be satisfied (you're not looking to be blown away, you just don't want a bad experience), which cuisine do you pick?
The most dangerous cuisine to try, in the United States at least, is Chinese. Your best working assumption is that the restaurant simply isn't any good. Even in a Chinatown, such as in New York or DC, most of the restaurants aren't very good. Inverting the two principles mentioned above puts you on a path toward figuring out why. Still, even in Paris or most of Europe for that matter, most of the Chinese restaurants aren't very good.
--Tyler Cowen, Marginal Revolution, providing non-Korean confirmation of my assertion about Korean cuisine in the U.S. Unfortunately, low variance means that the right tail of Korean cuisine is also largely missing from the U.S.