The usual suspects for me. I wonder if the National Policy had not been implemented, would Canada have mirrored the United States with its primary city on the east coast, Halifax, and smaller ones in its Great Lakes provinces. I suspect Montreal would've been on top either way, but I also suspect Halifax would've taken on a lot of the roles that allowed Toronto to boom and the Maritimes would probably be one of the dominant centres of the country today.
I wonder had we not given up our independence in 1933, or joined Canada in 1949, what it would be like? Assuming I still exist, what are my politics? Am I like some Albanian, from the poorest corner of North America, completely unimpressed with my country, desperate to afford some legal mechanism to emmigrate to Halifax or beyond? Or are we Iceland, a perfectly contented little country. They were certainly worse off than we were in 1949 - so if they could turn it around, perhaps we could've done as well.
I wonder if Quebec had voted to separate in 1995, where would we be now. I imagine a string of increasingly conservative federal governments would've strained relations between what's left of Canada to the extreme. I think 2018 is a long enough time for that to have pushed out BC, NS, PEI, and NL. Maybe we'd be under President Trump by now.
And finally I'd be curious to see what North America would be like today if colonization had never happened.