Mill Mountain Coffee and Tea has excellent sandwiches, and is vegetarian/vegan friendly. It has a special part in the menu that is for vegetarians, and any of the sandwiches can be made vegan by just omitting the cheese.
The atmosphere is nice, though a little cramped. Their coffee is very yummy, and they have several types...and also a whole section in the back right hand side as you go in the door for tea.
Cons: small, cramped, noisy