With such a wide variety of local "ethnic" restaurants, it seems almost impossible that there could be something new to add. But two offerings from Hippocrene Books are a good start towards exploring new flavors.
"Flavors of Burma" by Susan Chan is an introduction to an overlooked country twice the size of Vietnam, with wonderfully exotic dishes like spicy mango salad, perch with radish and pork curry with tamarind that is simultaneously sweet, sour and hot.
Gerbino and Kayal's "Taste of Syria" offers familiar-yet-new recipes, such as fried squash filled with lamb in lemon sauce, stuffed cabbaged seasoned with allspice and mint, and rosewater-flavored date cookies. The recipe for rhisthaya (lentil, spinach and noodle soup) is worth the price of the book. Both volumes give fascinating background into life and culture of the countries and people and will expand your eating horizon.