late night between Chicago & either Louisville or Cincinnati

Will be traveling from Lexington to Chicago and can go either I65 from Louisville or I74 from Cincinnati. The difference is negligible enough that I'll make my decision based on the better grub. I'm not leaving Lexington until 8-9p EDT, though, so I need a place open late (or 24 hours). Willing to do between Indianapolis and Chicago too if better options near Lafayette (thinking Purdue might help)?
 
Thanks!

Speaking of Purdue, Triple XXX in West Lafayette, IN would be ideal.  Really good burgers and root beer.  They are open 24 hrs., six day a week, closing at 10:00PM on Sunday nights.

Depending on the day of the week, and what time you want to stop, Camp Washington Chili, in Cincy, may work.
 
http://www.campwashingtonchili.com/index.cfm?fuseaction=home.viewPage&page_id=AAC19FDA-4757-12EB-A41C534ADCABDBA5