The Attendant is the place to go for good coffee and nice bites in London. It is close enough to the very popular Oxford Circus that anyone from out of town can easily stop by, and far enough that I have yet to find someone who looks like a tourist there.
Food and drinks aside the place is worth a visit just for its quirkiness. A former Victorian toilet built around 1890, the place (mothballed in the 1960's) sat dormant for almost 50 years before being reshaped into the coffee house we see today. It is a small space with one round table and high stools that face the original urinals (right, they are still there!). They also have a nice brunch option. Go. Downstairs, 27a Foley Street, W1W 6DY