I thought first of Liverpool, mainly because of the Beatles. I thought of Birmingham second, Manchester third, Newcastle fourth.
Manchester because that’s the name of my high school. Or York.
Newry
Oxford.
Because Tolkien. 
Or Norfolk because of Norfolk, Virginia. There are plenty of towns, cities and counties in Virginia named after ones from England or Scotland.
I’m from Midlothian and now live in Loudoun County, both Scottish names. My home county is Chesterfield, which also in English. I think it’s a county, not a city, though.
Birmingham, because I work with researchers at the university there (same reason Adelaide was my answer for Australia).
Kingston upon Hull
Manchester here as well. Leeds after that.
Bristol, mainly because I happened to have a meeting with a guy from Bristol last week.
Plymouth, because I live here.
I’m surprised so many are thinking of Manchester over Birmingham.
Peterborough.
Doncaster. My grandparents and my mother were from there.
Ely, for lots of reasons (lovely Cathedral!), but mostly because my SCA persona’s from there.
Aberdeen.
Southampton, then York, I imagine because I know people who currently live or formerly lived in those places.
Sorry, other way round. Norfolk in England is a county (county town Norwich). Chesterfield in England is a town, not a county (or a city, come to that).
And no-one has mentioned Edinburgh or Glasgow?
Nottingham came first to my mind. A former employer was based there.
Leeds.
Birmingham. I travel on Birmingham Drive on my daily commute to work.
Puddleby-on-the-Marsh.