Two great recommendations for you in Bloomington-Normal (on 39/51)…actually one in each of these twin towns.
In Bloomington, there’s the Lucca Grill, 116 E. Market (right in downtown Bloomington). This is as authentic a place as you’ll find in the land of big box chains. It’s a red sauce I-talian place, with great old school thin crust pizzas, served on little pedestal stands, with real peppers, pitchers of good beer, children running around, extended families, college students, and once in awhile, people breaking out into song.
At the other end of the food spectrum is a newish (one-year-old?) place on North St. (the main drag) in downtown Normal. It’s the Garlic Press Market Cafe, connected to a gourmet-gift store called the Garlic Press. The cafe brings in good bread from Chicago and bakes all their own cookies, cakes, scones, etc. Everything has a good foodie twist, with amazing "onion jam" on the roast beef sandwich or orange zest in the scones. Really good cheese, too. Oh, here’s a sort-of website: