The alphamegalog of the cities of Nebraska lists the largest city in Nebraska for each letter of the alphabet. In this case, ‘largest’ is based on population within the city proper.

Alliance
Bellevue
Columbus
David City
Eagle
Fremont
Grand Island
Hastings
Imperial
Juniata
Kearney
Lincoln
McCook
North Platte
Omaha
Papillion
(no Q)
Ralston
Scottsbluff
Tekamah
Utica
Valentine
Wayne
(no X)
York
(no Z)