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)
This may not be much of a secret but deserves a mention. I find it hard to go anywhere near this place without having to go there. Freshly baked Beigels hot salt beef and it never closes, 24 hours a day 7 days a week.