The Parthenon has a great assortment of vegan options. In addition to their separate menu listing of 4 entree items, there are others that can easily be modified if you don't mind asking the usual vegan questions. The owner is great, and occasionally comes out to talk to us about the vegan options and asks for feedback. Sometimes things are a little heavy on the oil and salt, but IMHO when you opt for Greek food it's not usually to save on calories :-) The portions are large, and it's a wonderful environment. They often have special dining nights, and there is usually a vegetarian/vegan option for those menus. During nice weather months their outdoor seating is available, and they have a weekly "bring your dog" event! Extensive wine menu also available.
Cons: not strickly veg, salt/oil heavy on occasion