The best place for a glass of wine*. It's the perfect balance – not too formal, not too informal either. Food is consistently good. Lamb's Conduit Street is a little oasis in the midst of Bloomsbury. (*slightly overpriced)
Being an East London boy at heart I am partial to an occasional fix of café culture. Pellici's has been running since the start of the last century, to which me, my father and my father's fathers have all enjoyed its mix of tasty Italian/London grub and energetic atmosphere. If you're visiting, make sure you drop by, as it will provide a valuable, forever-depleting education into what East London is really all about.