Obviously the big ones that I’ve personally experienced and come to mind immediately for me are
January 1999: probably the event that first got me interested in weather and being a snow weenie. I was 9 and the snow seemed impossibly deep.
December 2000: Not sure which storm in an epic month for Chicagoland but I vividly remember struggling to walk down the block in the deep snow with my dad so we could borrow the neighbors snowblower. That was also the month that convinced my parents to put a heater in the garage. Not sure I’ll ever see a snowpack that deep outside a lake belt or mountain chain again.
December 2009: Iowa, legit blizzard. Was in Iowa City so didn’t get the worst of it further west, but still ended up with nearly a foot of snow.
GHD 1: again in Iowa City so didn’t get the worst impacts but still saw 12” totals and significant travel impacts.
Winter 13/14: Working on graduate thesis in Iowa City. Seemed like we had something to track or sometimes 2-3 things at all times. Just a fun winter as has been said here countless times.
GHD 2 (was living in PA at the time so missed out, but was partaking in a different Midwest weather forum at the time and felt like I lived it vicariously)
Early March 2015: SE OH: Was working in the oilfield outside Woodsfield OH in the extreme SE corner of the state. Got blasted with 12-14” in about 8 hours. My little Honda Civic stood no chance driving those back holler Appalachian roads for days.
Mid April 2018: Nearly 16” of snow. Blizzard conditions and thundersnow! Biggest April storm in MSP history. Skied legit deep powder midwinter conditions the next day which was very strange for April 17 in Minnesota.
Note: I’ve been fortunate that in my short time in Minnesota I’ve experience the snowiest October (2020), February (2019) and April (2018) on Record.