Taylor Street Baristas is a little gem of a coffee shop run by some Australians, on New Street, just off Bishopsgate, in London. Two of my Aussie colleagues turned me on to this place when I lamented the lack of non-Starbucks, non-Coffee Republic, non-Caffe Nero, real coffee, and the fact that my all-time, lifetime favorite, Monmouth Coffee in Borough Market, was too far away from the office for emergencies. Taylor Street is for serious coffee drinkers, as they say themselves. Anyplace whose website exhorts you to "time the extraction, listen to the milk," is pretty much gonna know how to make a damn fine latte. And they do. And for cheaper than Starbucks, which is, in London as in the rest of the world, ubiquitous (or omnipresent? Not sure).
When I made the great vegan switchover, I feared I would be stuck with Starbucks as they are soya-literate, and alot of coffee places in the UK are not. Not to fear, however: Taylor Street does soy, and for only 40p extra, which puts them pretty much on par with Starbucks, price-wise (when you're already paying 3 quid for a latte, these things count). It's worth the extra 20p or so, though, to be served by someone who remembers you by name.