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

Attleboro
Boston
Cambridge
Dartmouth
Everett
Fall River
Gloucester
Haverhill
Ipswitch
Jefferson
Kingston
Lowell
Malden
New Bedford
Oxford
Plymouth
Quincy
Revere
Springfield
Taunton
Uxbridge
Vineyard Haven
Worcester
(no X)
Yarmouth
(no Z)