This is a very broad question. It all depends on what is important to you.
Waterloo is a nice University-centric town with good industries, job opportunities and community life. Milton is similar, perhaps larger, with lots of up-and-coming amenities and development. Both cities are pridefully Ontarian in nature, meaning we are blessed with good communities, schools, healthcare, kids recreation, etc. in basically all parts of the city. If you are looking for something specific in terms of housing neighbourhood, contact me through email or phone/WhatsApp and I can assist you there.
When are you moving to Canada?