I am gluten free as well, which further limits my choices at restaurants and especially on the road. Chipotle is a life-saver for me in that vein. If you aren't gluten free and are just looking for veg options in most smaller towns, Taco Bell is probably the best bet. They are awesome with substitutions (try subbing potatoes or rice for the meat). For vegan, order fresco style to get the fresh salsa in place of cheese/sour cream. The guac is vegan.
Prior to having to go gluten free, we really enjoyed Feast BBQ's smoked tofu. It is dredged in flour and fried, so I can't have it anymore.

Other favorites:
Earth Friends Cafe has a ton of vegetarian and vegan options, all tasty, with GF options.
Dragon King's Daughter - Vegetable Fried Rice, Spicy Tofu Roll (which is not really spicy but very tasty and filling thanks to the avocado on top), Vegetable Roll (light and not filling but tasty)
Martini Italian Bistro - Spaghetti Primavera (they offer GF pasta as well and are trained in avoiding cross contamination)
Taco Punk - Seasonal Veggie Mole Tacos....my favorite is when they are using kale and potatoes in spring and fall