London — Fitzrovia
Kaffeine

Photo: Bex Walton, CC BY 2.0
One of the shops credited with bringing an Antipodean flat-white sensibility to London in the early 2000s, still recognizable by its white subway tile, oak paneling, and a neon sign that's become something of a Fitzrovia landmark in its own right. Fitzrovia sits just north of Oxford Street and has long been a base for advertising agencies, publishers, and media companies, which shows in the steady stream of laptop-and-meeting traffic that keeps the tables turning through the day. It runs a full breakfast and lunch kitchen alongside the coffee program, treating the space as a proper daytime restaurant rather than a coffee stop with snacks bolted on.
A second branch on Eastcastle Street covers the overflow when this one's full, which is often, particularly around midday. Open all seven days, unusually for a shop this specialty-coffee-focused — most of its more purist peers close at least one day a week.