The obvious choice for me is January 2019. Hard to beat 10" of snow with little to no mixing or accumulation issues. Also feels good to be in the bullseye, though not the bullseye of the bullseye (congrats, MoCo). My second choice for MBY would actually be the March 2017 storm - I know that it was a moderate bust in the NW suburbs when the mixing line sprinted west overnight, but the forecast was fine around 95, and despite it being mid-march, the large amount of precipitation in that 2-3 inch block of sleet, ice and snow persisted far longer than I would've thought. Made the next several days feel very wintry. And any snow in the middle of March is pretty cool for this area, though it has become pretty common in the 2010s
I think we should get an interesting variety of answers...the January 2019 storm was not an area wide crusher, and that there has been some pretty sharp cutoffs in some of these storms.