They've never beaten Nebraska. Full list, including 8 POWER FIVE teams. Technically, there are 10 Power 5 teams who have never beaten us, two of them just happen to be the crappy johnny-come-latelies in the Big Ten East.
Akron
Arkansas State
Ball State
Cal
Cincinnati
Colorado State
Florida
Florida Atlantic
Fresno State
Louisiana Tech
Louisiana-Lafayette
Middle Tennessee State
Mississippi State
Nevada
New Mexico
New Mexico State
North Carolina
North Carolina State
North Texas
Rice
San Jose State
South Alabama
UAB
UCF
UNLV
Utah
Utah State
Wake Forest
West Virginia
Western Michigan
Wyoming
Akron
Arkansas State
Ball State
Cal
Cincinnati
Colorado State
Florida
Florida Atlantic
Fresno State
Louisiana Tech
Louisiana-Lafayette
Middle Tennessee State
Mississippi State
Nevada
New Mexico
New Mexico State
North Carolina
North Carolina State
North Texas
Rice
San Jose State
South Alabama
UAB
UCF
UNLV
Utah
Utah State
Wake Forest
West Virginia
Western Michigan
Wyoming