For me it'd have to be 1983. Wins over UCLA & Air Force. Great bowl win over Missouri.
According to the AP this is how our final top 25 seasons have fared:
1984 1
1996 5
1983 7
2020 11
1980 12
2009 12
1979 13
1981 13
2007 14
1985 16
2006 16
1994 18
2021 19
1977 20
1989 22
1990 22
1991 23
2001 25
2008 25
I was surprised 2011 didn't make the top 25. It was our only "10 win" season not to do so (10-3 that year).
May 2024 join the top of the list.