To answer upthread:
* RAF Lakenheath
The largest US Air Force base in England, with the only F-35/F-15 fighter wing in the US Air Forces in Europe (USAFE). It's located in Suffolk County, East Anglia, about 80 miles northeast of London.
RAF Croughton
The main base for the CIA in Britain, and also a USAF communications station. It's located in Northamptonshire.
RAF Mildenhall
Located in Suffolk, East Anglia, and part of the Tri-Base area along with RAF Lakenheath and RAF Feltwell.
RAF Alconbury
Includes a bomber forward operating location, theater munitions storage and movement, and global command and control communications.
RAF Molesworth
Previously had a GLCM unit that was inactivated in 1989.
Bude, Cornwall
Jointly run by the NSA and GCHQ, Britain's largest intelligence agency.
Other US military bases in the UK include RAF Welford, RAF Fairford, RAF Feltwell, RAF Upwood, RAF Barford St John, RAF Blenheim Crescent, RAF Fylingdales, and RAF Menwith Hill
The US intelligence community also has a large but secret presence in the UK. The UK government has not disclosed which US agencies are working in Britain or their deployment levels.