There is little doubt that overall the most effective artillery was French. Brilliant organization, effective standartization, highly trained men and officers due to tradition and much love by Napoleon. Of course part of the great impact it made in the large battles is also due to the tactical genius of Napoleon, which usually deployed it where it's strenghts could shine.

Still the Russian Artillery was quite surly the best of the Allies, with a huge number of guns and very brave and well trained men serving them.