Central School of Speech and Drama, you mean?
That one seems to be the most expensive, but I've never heard anything bad about it. I know a lot of famous actors/presenters went there to study acting but I don't have a clue who's studied writing there.
I think Goldsmiths does a screenwriting MA, but while I know their creative writing one is brilliant, I know nothing about that one. One to look into, maybe, if you haven't already.