Can I just throw in a vote for the Keg? Have dined at both the Banff & Winnipeg locations and was thoroughly impressed with the quality of food, level of service and price.

But going more down the track of what constitutes a chain, the Conran places i've dined at in London are very popular - if somewhat pricey - when comapred to N. America (and that's before you count the somewhat sorry state of the US peso )