Illinois has a lot to offer! Chicagoland aside, I spent a fascinating day at the Illinois Railroad Museum in Union, IL last year (Best RR museum in the USA, by a country mile!).
Peoria, where I spent a few months last year / earlier this year, is an amazing place for varied action. UP, BNSF, CN and NS all appear, along with a number of shortlines / class B railroads - IAIS, TP&W, and Keokuk Junction (who regularly use an A-B-A set of FP9s on freight!). Lots of unit variety too - even some green and whiteface BN to be seen..