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.
I love the George and Dragon Public House. Cluttered deco of silly artifacts and memorabilia and slightly scuzzy around the edges. Great drinking characters, DJs and The White Cubicle gallery in the ladies toilets is difficult to beat.
There are many quirky book stores in London, but I really love the selection that Daunt Books have, they often have bespoke editions which you won't find in other book stores. Also, the people that work there are so helpful and knowledgable. I can never stop myself from walking in!
Melrose and Morgan is a grocery shop and kitchen providing freshly prepared food and artisan products in the heart of Primrose Hill and Hampstead Village.