O'Hanlons Port Stout for me if I can get, Bass in the Dolphin on the Barbican, When op norf I'm partial to pint of Camerons Strongarm or Timothy Taylors Landlord failing that the darkest beer I can find upto about 4.8%.
The Euston Tap just outside a station with a similar name usually has a good selection of Stouts and Porters.
SS