Remote-work friendly cafe, Ozone, at Old Street Station in London has Wi-Fi, plugs, lots of space, and great single-origin coffee.
Independent roaster Fjord Coffee Roaster has their specialty coffee shop, Silo Coffee, in Kreuzberg, East Berlin. Wifi available & remote-work friendly.
Five Elephant in Kreuzberg, Berlin is a micro-roaster and specialty coffee shop. Plugs available for remote work.