Which cell phone carrier has the best COVERAGE in Markham, ON, Canada? [Hepburn, timbercircle, FMM high school, Miliken Mills High School, etc.]

Meaning has high signals (outside and inside such as basements), won't drop calls, fast internet speeds, etc.

I have looked at tonnes of reviews for each company and pretty much ONLY hear BAD things...

My number one priority is coverage and signal.
then comes things such as price, customer service, phones, etc.

Also are there any better carriers in Canada that I did not mention?

Thanks a bunch!