Ichiban and Fugu cook a lot of their dishes in pig fat, even the vegetable ones. If you're a strict vegetarian (or some flavor of non-pork eater), you might bear that in mind. They can use another oil if you ask.
A vegan co-worker was a big fan of Wong's Garden on Atwood. He had developed a good relationship with the owners and they were willing to modify recipes to meet his needs. Jury's still out on Wong's successor, Magic Wok.
Wah kee noodle is good if you explain your preferences. Their broth and their noodles are not veg of course but they will make a nice vegetable and rice dish for vegetarian diners. Also Ha Long Bay (sp?) has some great veg dishes.