For Taipei restaurants, the original Din Tai Fung (on Xinyi, and only because I've never been to any other in Taiwan) and Yong Kang Beef Noodles. For specific foods, the black pepper bun near eastern entrance of the Raohe Night Market and the green onion pancake under the Thanh Ky restaurant sign (near the original Din Tai Fung; it's not part of Thanh Ky, but resides right under the restaurant's sign on the corner).