Superb Soho Coffee
Flat White in Soho makes coffee for people who actually like the stuff. London has awful coffee, few people will argue with that and the proliferation of Starbucks and Cafe Nero is proof positive.
Flat White is run by Australians and Kiwis and they make a liquid recognisable as coffee. No syrups, double whoppa frappacinos, just proper coffees.
Great sweet treats as well as good solid breakfast stuff, Flat White is a bustling cafe in the true sense of the word. It's also across the road from the brilliant Yauatcha.
This tip has the address "Berwick Street Market, Soho"