I got this useful list from a deceased blog so to avoid to lose it, I am reproducing it below (with comments included).
Thanks goes to The Berlin Review
If you want to buy English books in Berlin it is not all that difficult, and the city is quite well-served, although if you are looking for something very specific you may have to wait whilst they order it for you, and in that instance you would be better off with Amazon.de or one of those websites.
But sometimes going to a bookshop and browsing the shelves offers something that Amazon can’t offer, whatever the selection or the prices they have online. So here is the Berlin Review guide to English Bookshops in Berlin. Check them out…