Ade Clarke

How about The Lamb on Holloway Road? Just a couple of hundred yards north of Highbury Corner. Free of tie, so three regularly changing and interesting cask ales (often from London Breweries) plus three Camden Town Brewery beers on keg, Guinness etc. Weekly Irish and bluegrass music sessions in a proper boozer.

The Pub Doctor

The Compton Arms is by far the best - and the only proper old fashioned pub left - in this area.
The others mentioned all come in flat pack form. If you like the stereotype of branded, soulless bars then this appears to be a great list in its current form.