Neil Young.
Rush doesn’t even make the first round cut.
Neil Young/Stephen Stills, The Guess Who, Rush. I love each for different reasons, hard to put any one above the others. If I had HAD to, I’d go with Neil.
Skinny Puppy.
Tragically Hip
The Dayglo Abortions. 
Another vote for Leonard Cohen. Second only to Bob Dylan in my mind.
Paul Shaffer
Joni Mitchell, The Tragically Hip, Sam Roberts Band, Stars, The Jerry Cans, Jeremy Dutcher, Leonard Cohen, various Canadian classical composers…
As well, I’m a musician and I have many musician friends in the music business here in Canada, whose music I love.
I just love Canadian music. I can’t choose just one band/artist.
Mr. Tambourine Man? MR. TAMBOURINE MAN!!
There needs to be a consolidation of the choices and a proper vote.
Not already suggested:
Red Rider
Doug & The Slugs
Trooper
Arcade Fire
Bruce Cockburn
Anne Murray
Buffy Saint-Marie
ETA: The New Pornographers
This
No love for Glenn Gould?
Bare Naked Ladies - recent inductees to the Canadian Rock and Roll HOF and just a fun group of guys.
Gordon Lightfoot would probably be my third choice.
Although I picked Rush, I personally prefer Neil Young. Joni’s OK but a little eccentric, or different than my tastes, but she’s certainly talented.
Not mentioned yet but I always liked Prism, Streetheart, Doug & the Slugs and Chiliwack.
They’re the judges.
No love for Matthew Good (or Matthew Good Band), or Sarah McLachlan?
Okay so not as influential as Neil Young, Joni Mitchell or Rush, but certainly more prominent on my personal playlist.
Guy Lombardo.
Rush is better than every other choice in this thread combined
Up to this point in History, I would go with the Tragically Hip.