OH and the Cheesecake Factory has an awesome portobello burger. it's delicious but expensive.
Mellow Mushroom has vegetarian options and vegan options. They have a good avocado sandwich, a portabella sandwich, a tempeh sandwich, and pizzas and calzones with your choice of topics. I get my pizza without cheese. They also have a gluten free menu. I am from Huntsville and I usually stick to Sitar, Surin of Thailand, Thai Garden (any dish you can replace meat with mixed veggies or tofu), Jason's Deli (great veggie wrap), and Phil Sandoval's (they have vegetable enchiladas, vegetable fajitas, vegetable burrito and offer vegetarian beans and rice). There are a few places near Oakwood University that have plenty of veggie options too, because they are vegetarians.