Traveling I -55 south to Springfield Ill
In Springfield there are a number of decent places. Of course it all depends on what you are looking for.
D'Arcy's Pint is a nice place for pub food---try the Buffalo chicken horseshoe (a local specialty) and a Guinness Draft.
Tuscany is a decent casual Italian spot with an interesting menu.
Augie's Front Burner downtown is always good.
Little Saigon is a Thai/Vietnamese operation that is as good as any I've had anywhere...it's only been open for a few months...try the Sate Bo or the French Beef Chunks.
Cozy Dog on south 6th street claims to be the originator of the corndog...don't know if it's true, but the corndogs are as good as they get.
Cafe Brio and Bentohs downtown would be excellent lunch choices.
If there is something else you're looking for let me know (or if you need to know where these are at).