It depends entirely on if you want an MSc in Epi or an MPH. For the MSc, the best is McGill > Queens/Ottawa For the MPH, the best is UofT (they don't have an MSc in epi) McMaster doesn't have a MSc in Epi, but they do have one in Health Research Methodology that is quite well regarded. Waterloo doesn't have a MSc or MPH in epidemiology - it's more generic in public health and is not highly regarded.

You seem to keep asking the same questions over and over again, so I think you first need to decide what it is exactly you want to do - MSc, MPH, epidemiology, economics etc. and then figure out what the best program is for you (and not the 'easiest to get into').