It's been year since I went, so I guess this would be a last resort, but Lajoie on Lajoie street(corner Champagneur) had a decent poutine.
Technically Mile-end, but close enough is Cafe Local on St-Viateur, their poutine is good, altough in a slightly ''upscaled'' way.
There must be better options that this, I just can't think of them. Don't know what the poutine is like at Lesters' on Bernard, that might be a safe spot to try traditionnal poutine.
200 Rue Saint-Viateur W, Montreal, QC H2T2L5, CA