The best thing about any charity shop is that you never know what you are going to find. I have a well tested route around London that includes all of my favourite charity shops. This Oxfam has a great selection of books and often turns up some interesting clothes too.
This is one of the only platforms on the London Underground that is not bombarded with billboard advertising. It's a reminder to myself of how an uncluttered environment can give you so much more room to think.