On memory from quite awhile back, and in no order. I don't even know if all of these are around anymore but:
Black Sheep Ale, Timothy Taylor Landlord, Taddy Porter, Oatmeal Stout (both Sam Smith), Old Peculier, Highgate Mild, Fuller's London Pride and Chiswick Bitter, Young's Special Bitter, Thomas Hardy's, Orkney Dark Island and Skullsplitter, Hook Norton, Mackeson's Milk Stout, Hopback Summer Lightning, Shepherd Neame Spitfire (I understand this is not what it once was - I used to really enjoy this), Adnam's, Charles Wells Bombardier, Belhaven 80, Young's Winter Warmer.
I know I'm missing a million bitters and/or pales (does Worthington White Shield exist still?), and IPAs. But these were some of my favorites from either a trip there many years ago, or what I could count on getting in Chicago.