This is a college town in Isan, which means cheap, plentiful, and unapologetically regional. You will eat well for 40 to 80 baht a meal almost anywhere; you will rarely eat anything dull. The standard Isan trio of som tam (papaya salad), gai yang (grilled chicken with sticky rice), and laap (a minced-meat salad with herbs, lime, roasted rice powder, and a great deal of chilli) is on every menu and gets better the further you get from the centre.
The food street that opens each evening around the central fresh market and clock tower is the best single place to graze. The other obvious zones are the streets running directly outside the downtown MSU gate, where students keep half a dozen noodle-soup, khao man gai, and stir-fry stalls in business until late, and the side streets around the Khamriang campus, which run cheaper and rougher. Look for gaeng om (a fragrant Isan herb stew), sai krok Isan (fermented rice-and-pork sausages), and neua dad diao (sun-dried beef, deep-fried until crisp).