The homemade biscuit, as a food icon, does not seem to resonate strongly in Chicago. I guess it's just one of those things that you should look for at the source. Can't expect one city to do EVERYTHING for me. At any rate, I did find a very good homemade biscuit (large, flaky yet fluffy) the other morning at:
1800 W. Grand Ave
But the gravy wasn't quite thick enough. Everything I saw people eating looked great at this place, and everyone seemed to be very happy with their food. Super-nice servers, Intelligencia coffee, and the clean, comfortable space were bonuses.
I had also pinned slight hopes on the Breakfast Club, at 1381 W. Hubbard, but after spying the biscuits being delivered in a box from a bakery, I decided to order something else. The French toast was perfect. Portions were massive -- and so were many of the patrons. Again, a nice clean pleasant space with a very efficient and friendly staff. Extremely crowded, though.
Finally, based on advice gleaned here, I did try the biscuits at the hipster hangout, Flying Saucer (1123 N. California) and found them to be quite good, but the gravy had no oomph (too little grease, perhaps) and was served with scallions (not a bonus, for me). Negatives include a hung-over staff and relatively high prices, but the coffee was excellent.