The Australian Research Council, as part of a program to assess Australian research efforts, has rated English-language journals in the sciences and in the humanities and creative arts, including law. According to the background page:
A journal’s quality rating represents the overall quality of the journal. This is defined in terms of how it compares with other journals and should not be confused with its relevance or importance to a particular discipline. There are four tiers of quality rating [A* = top 5%; A = next 15%; B = next 30%; C = bottom 50%] and their definitions can be found here.
The rankings were developed in consultation with the relevant Australian Learned Academies and other institutions, the list of which is available here.
Ranking lists are available in Excel format.
Happily, there are three Canadian journals on the A-plus list: the McGill Law Journal, the Osgoode Hall Law Journal, and the University of Toronto Law Journal.