best delicatessen in london
Billy's Downtown Deli on Dundas Street is your best bet. They are known for their sandwiches, breakfasts and pies.
I've never eaten at Pancer's or Centre St, so I have no idea how they compare.
Billy's Downtown Deli
113 Dundas St, London, ON N6A1E8, CA
Hope you enjoy London. ;-)
Here's the most comprehensive thread about dining in London, including current suggestions and comments near the end of the thread: http://chowhound.chow.com/topics/664302
Here's the most recent thread about dining in London: