The streets were paved with coffee

As I sit on the not so speedy train to London I've been reading this rather interesting article about the past of London's coffee houses. A far cry from today's Starbucks or Pret where very few strangers will share a glance across a cup of flat white, let alone ask the opinion of another customer.
Anyone wishing to share their favourite independent coffee shop in London for me to sample this weekend?

http://www.telegraph.co.uk/travel/destinations/europe/uk/london/9153317/London-cafes-the-surprising-history-of-Londons-lost-coffeehouses.html