Brighton
I live outside of San Francisco but I have developed a second life in Brighton. There is a lot to do in Brighton. Much of gay life is centered around St. James Street. It does not have the glitch of London but there a small pubs, dance clubs. And the city in general is pretty gay-positive. And with the change in liquor laws, you can party all night at the Bulldog and a couple other pubs on weekend.
The Pavilion is worth a good visit. Brighton has the highest number of restaurants in England outside of London. Shopping is very good - much of it centered around Churchill Square. Although not the theaters of London, Brighton is on the circuit for concerts, plays, etc. Always a full schedule of events.
It's close to Gatwick and there a thousands of airline employees who live in Brighton. Some pretty hot crew that live there and would travel down from the airport. Unfortunately, most of the trans-Atlantic flights have now moved to Heathrow. I have made 'friends' with crew from all of the major US airlines while visiting Brighton.
There is also ferry from NewHaven, about 20 minutes from Brighton to Dieppe, France - a fishing village.
I went to Manchester a couple of years ago and fell in love with the city - very friendly in the gay village. It rains a fair amount but the Northern England has the reputation of being friendlier than London and I found it to be definitely true.