My daughter's been a vegetarian for years, and we live in Mill Valley, so we've tried a lot of places. We don't go out of our way to find veggie restaurants, since most places have several veggie choices on their menus. Places we like are:
Avatar's Punjabi Burritos (more of a lunch place)
Avatar's (related and at the north end of Sausalito, but really good for lunch or dinner)
Fishman Village (Chinese)
The Anchorage (also north end of Sausalito - great breakfasts and Mexican food - I'm addicted to their Huevos Montana)
Hope you enjoy some of these!