Another one for BBC TV centre - I bloody loved that building and the fact that you could sit in all the observation galleries and watch programmes being made and hear gallery talkback. I particularly loved all the tea bars close to the studios and the waitress service restaurant. I actually cried when they shut it down to make (mostly) luxury flats.
I also worked at Thames TV studios at Teddington Lock (shut down for flats), the old Coronation Street set in Manchester (torn down for redevelopment) and am currently in the ITV building on the Southbank, formerly LWT (about to be redeveloped into luxury flats... can you see a theme here?) The main thing in common apart from the famous people and wonderful programme making and a real sense of telly history, is the fact that past the fancy receptions, they all looked like really messy sixth form common rooms.
I also worked in One Canada Square - and was in the building when the canary wharf bomb went off.
Other than that I've filmed all over the place: got to make the top of the Post Office Tower go round, did the dome and the eye before they opened, numerous castles and historical buildings, Downing Street, Houses of Commons, film sets, TV drama and soap sets... The best bit is filming early in the morning or late at night when no-one is there.
Ironically, I'm about to spend the next five years back at the old BBC building as there are a couple of studios there still and ITV are moving in. I feel sad - it will be weird going back to a sanitised version of the building I loved. And I will miss the daily joy of working next to the Thames with a view of the river, the eye and St Paul's out of our office windows.