Go to Bells Eccentric Cafe. They have beers that are only on tap there.
Close by are Shakespears, which is a multitap in the old Shakespear rod and real offices, and the Kalamazoo Beer Exchange. The Beer Exchange has market pricing on the screens, as more order a beer the price goes up, no orders and it goes down.
A little farther is the Central City Taphouse, a more upscale taproom. This is on the old pedestrian mall south of the Radisson Hotel.
Edit - Bells production brewery is in Galesburg, and you can take a self guided tour of the new brewhouse now. No beer, but it is impressive.