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

Antrim
Berlin
Concord
Dover
Exeter
Franklin
Goffstown
Hudson
(no I)
Jaffrey
Keene
Laconia
Manchester
Nashua
(no O)
Portsmouth
(no Q)
Rochester
Somersworth
Tilton Northfield
Union
(no V)
Wolfeboro
(no X)
(no Y)
(no Z)