The city in Southern Illinois of Carbondale is home to the campus of SIU-C (Southern Illinois University at Carbondale). This is a predominately liberal school that has had it's charter for around 150 years. This is just a little background of the town. It explains why there are so many options for vegetarian cuisine.
The general consensus with most of the vegetarians that I know always name the same restaurant as the top. I will admit that I don't fall into this group completely. A wonderful woman that I dated showed me the benefits of not eating meat. While I haven't made the complete jump, I probably eat around 1/10 of the meat of an average American.
Coming in at number one is a little cafe. It is know for its great selections of coffee as much for it's entire menu of vegetarian dishes. The name of this fine establishment, The Longbranch. Any food that us carnivores might enjoy, you can get at The Longbranch. One of the top notch dishes are their biscuits and gravy. Ho-made biscuits and soysage gravy. It is quite a treat, even if the sausage doesn't come from the mainstay animal that feeds most carnivores: the pig.
Of course The Longbranch is not your only option. Another great choice is Harbaugh's Cafe. It serves breakfast and lunch. It is so popular that you will usually have to wait in line to get a table. While they don't only have vegetarian dishes on the menu, these seem to be the most popular. Any kind of food that you may want, they offer the vegetarian equivalent of that dish. The food is great and the prices are reasonable, leaning on the expensive side. The quality of the food more than makes up for the additional cost.
One last resturant that specializes in the vegetarian market is the grocery store that is known as the Neighborhood Coop. As stated, it's primary purpose is to sell locally grown produce and organic groceries. This store is quite expensive, but even if you don't care about your health to that level, the ingredients that are available will make any dish that you cook taste much better. They have a cafe in the store that sells vegetarian food that ranges from pasta dishes to pizza to deli sandwiches.
If none of these three restaurants spark your interest, have no fear, almost all of the restaurants in Carbondale offer at least a couple of items that are vegetarian. This gives you many, many choices.
Not only are the dishes offered vegetarian, many go that extra step and are certified vegan. The point is, if you don't eat meat, Carbondale Illinois is a great town to go and get a bite to eat. You will find that for a town that has a permanent population of 20,000 and another 20,000 students during the school year, there are more vegetarian choices than you will find in cities much bigger in size.