Well, if Six Flags Great America is getting a S&S 4D Free Spin in 2017, wouldn't it be the first of its kind in the Midwest? I also feel like if they do,I think it's gonna be themed to the Joker since it would be in the Mardi Gras area of the park and well, the Joker could blend well into the Mardi Gras theme.
For a coaster that I've been on, I like Thunderbird's, Batman: The Ride (almost all of them) and Storm Chaser, but for one I haven't been on, its probably Valravn at night and Phobia Phear Coaster.