For a vegan breakfast in Madison, Sunroom is definitely a contender. I've been here a few times and the servers always suggest the tofu scramble and the breakfast burrito vegan-style. They don't have veggie options for substituting one veggie for another so it helps if you like mushrooms, especially if you get the tofu scramble which is packed with them. Most of mine ended up on the side of my plate. Also on the menu is oatmeal with bananas and raisins, fruit cups, and customized fruit smoothies. It might not be the most diverse vegan breakfast menu (don't get your hopes up for pancakes or waffles) but they've got a good start and a staff that knows what's up for vegans.
Besides having some decent vegan options, the Sunroom is currently at the top of my list for vegan breakfast because of the setting and atmosphere. Parking is easy (I park in the North Frances lot) and precedes a short walk on State Street to get to Sunroom. It's a cozy, intimate, diner-style venue upstairs with a nice view of State Street if you grab the right table. Local art is on the wall and there's plenty of Madison publications near the door for you to read while you dine solo if that's your thing. Perfect for a lazy vegan Sunday!!