The cuisine of the rural northeast is a must-try for every foodie, and few places in Bangkok do Isaan food better than long-standing Somtum Der. The restaurant, which now boasts outlets in New York, Taipei and Tokyo, serves a range of spicy salads, fish dishes and grilled meats, as well as an encyclopaedic array of som tam (papaya salad). Try the latter with pla duk foo (fried and flaked catfish).