What is Taiwanese snack food? It's stuff like popcorn chicken and fried stinky tofu, both of which are very good here (although the best stinky tofu in the area, abstractpoet says, is at Joy, a solid Taiwanese-run restaurant). Grand Harbor's chefs fry well, and the fried pork chop rice plate, a sort of bento with rice, tofu, veggies, and a soy sauce–braised egg, is a nice rendition of a typical Taiwanese lunch.
Grand Harbor also has decent versions of oyster pancake and intestine stuffed with Chinese sausage and rice. A surprisingly good option is the chef's special intestine, stir-fried with ginger, preserved mustard greens, and bamboo shoots. It's pleasantly sour, and lighter than you'd expect.
Over in Santa Clara, Mama Chen is more like home-style Taiwanese food. Yes, "Mama" is actually doing the cooking. "The oyster pancake there was one of the more authentic ones I've had in the Bay Area," says luckytomato. There's a shrimp version, too. Here the pork chop is nicely seasoned, and the green onion pancake is thin and crisp. They do tend to run out of things, though.
Grand Harbor [East Bay]
46577 Mission Boulevard #415, Fremont
Joy Restaurant [Peninsula]
1489 Beach Park Boulevard, Foster City
Mama Chen [South Bay]
5075 Stevens Creek Boulevard, Santa Clara