Not the most exciting place inside, but a lovely rooftop area which not all that many people seem to know about, 2 mins walk from Old St station. If it’s packed then The Red Lion is just up the road.
A short walk from Oxford Circus tube station, Kaffeine is easily one of the best coffee houses in London. Whenever I'm working in the area I pop in beforehand to kick start my day with a well-made cappuccino.
Cosy little restaurant with a giant kitchen island unit in the centre which doubles as a display and seating area. Open for breakfast, lunch and dinner with a focus on fermenting.