A Few Possibilities By Year-
2016 - Nebraska beat Oregon 35 to 32 & Northwestern 24-13 helping to start the year 7-0. Hopes were high until the loss to Wisconsin & the Ohio State beat down.
2017 - ?? Nebraska beat Illinois 28-6
2018 - Nebraska beat Minnesota 53-28 & Michigan State in the snow 9-6 (both felt like good wins at the time as we were gaining momentum.
2019 - ?? Maybe Nebraska over Maryland 54-7 or Illinois 42-38 in a shootout. In reality nothing felt good about that season.
2020 - ?? Nebraska over Penn State 30-23. It felt good to get the win but it didn't feel like a good win at the time.
Not many "impressive" wins to choose from but if I had to pick 3 games that were impressive, one would be the close loss to Ohio State in 2018, One would be the win over a rising Minnesota team in 2018, and the third would maybe be the Northwestern game from 2016. That took us to 4-0 and it felt like we were on a different trajectory from years past. Players were believing and fans were starting to get excited.