Try Handlebar Cafe 2300 block of North Ave in Wicker Park / Bucktown area. it's a few blocks from the Damen stop on the blue line. It's a pesco-vegetarian restaurant i guess, in that they serve fish with two or three dishes, everything else is vegan / vegetarian. Great drink specials to.
I know this thread was started about a year ago - but I just joined the Chicago blogger group and I'm vegetarian (trying to go vegan, but I still eat cheese). Just down the street from me in Boystown is Chicago Diner - www.veggiediner.com It's on Halsted between Roscoe and Newport
It. Is. AMAZING. Whole Foods sells Chicago Diner vegan baked goods too, which is super exciting.
I'm not a vegan, or vegetarian even (not even close), but agree with the veggie diner baked goods at Whole Foods - really, really good. Also, not really fancy and more of a lunch stop, but the new Chicago French Market at Ogilvy has some delicious looking options - there's this great organic veggie and fruit juice stand and a booth called, Raw, that sells vegan pizzas, desserts, etc.