Gordon's Wine Bar
Location: 47 Villiers Street, London WC2N 6NE
This is London's oldest wine bar (est 1890) -- judging by the cramped confines people were much smaller then.
Go to Gordon's, go straight to Gordon's, do not pass go, do not collect $200 (actually, the $200 might come in handy).
Meels and I had many brilliant nights here, including our first wedding (not sure how official it was seeing as the 'Wedding Certificate' was actually a train ticket).