I'm currently doing a music tech course in London and looking for further education. I want to study sound design for games and movies but I'm not sure which are the best universities to consider. If someone could offer advise that would be great, they need to be in London or easily accessible by train from London.
For games you can consider joining a game development team/company instead of enrolling in the university. Choose small ones so you can be directly involving and talking with senior sound designers there.
I'm not sure which are the best universities to consider.
I'd say none, because I think most formal courses in sound are either about studying trivial BS or a valuable business for its staff, or both. You can do so much more, if you just have a look and a go at it yourself, because there's really nothing preventing one from self-studying and it's also a rather non-painful process (even more so when you can use the best resources and the most motivating practices you can find), because the field is simple and concise in technical practice as well as in theory.
Now if you'd like to do something formally, then you could probably try applying here: http://nftsfilm-tv.ac.uk/our-courses/diploma/sound-recording-film-television, as it's decently appreciated by industry professionals. For game audio I'd probably look at http://school.videogameaudio.com/apply/ as it's an online course and covers only the things that are particularly different in game audio compared to linear media. For a different take on game audio, I'd suggest computer science / IT over sound production courses.
WOuld probaly second what @Internet Human said, you will pay thousands to get MAYBE a handful of courses tailored to you. For (I believe) less that 300 USD you can get a fairly in-depth (based on things that I've heard) learning experience from video game audio school at least to get a start. Fmod has a wealth of tutorial videos up on that program as well.