US 66 is rotten ride, from Chicago to St Louis, its flat and boring beyond belief.
If you want to ride across Illinois and Iowa to Omaha, you can have plenty of wonderful roads and scenery, though their are areas of Illinois and Iowa that are flat, most are rolling hills, and in NW Illinois and NE Iowa the hills are wonderful riding and the bluffs along the upper Mississippi gorgeous(like now with the colors New Englandesque). Depending on the time you want to dedicate to touring, I can come up with nice riding paths from Chicago that are enjoyable, the first hour out of the suburbs will be prairie and the father west you go the more hills and curves you get.
Go west on IL72 to Byron, IL
Then go South on IL2 along the Rock River to Dixon, IL( this is a nice winding road that hugs the river). From there go west on US52, you can take this to Savanna, IL, cross over into Iowa and go North to Dubuque, IA. Very nice along the Mississippi(near St Donatus, its compared to Luxembourg). Or..take US 52 to Mt Carroll, IL, go north on IL 78 to US 20, then go west on US 20 through historic Galena(where US Grant lived, and also a portion of The Field of Dreams was filmed) and continue to Dubuque, IA.
From Dubuque, great riding north is a hoot, on the Balltown road(C9Y) and to Gutenberg and to Marquette....but north of Dubuque is out of your way.
Go west on US20 to Dyersville(20 to 25 miles) and you have arrived in the town where most of The Field of Dreams was filmed, and you can visit the ball field north and east of town.
Otherwise, if you want to go on to Omaha, then take US 61 south to US 151 to Cedar Rapids(you will go through Anamosa, IA and the National Motorcycle Museum is there and very nice. After Anamosa, proceed towards Cedar Rapids, as you come into Marion(before Cedar Rapids, take IA 13 south to US 30 west, and then connect with US 151 south again (this bypasses the city), US 151 will take you through the Amana colonies and at Homestead you will connect with US 6. US 6 is mostly two lane and a nice ride towards Des Moines and if you choose will take you to Omaha.
There are more paths, but thats a bit of a start for you.
