Hmm...
CFL - easy, Bombers though I'll confess I'm not nearly as fanatical as many others here. I absolutely admire the dedication of the fans that went through that 1992-2017 era.
NFL - Vikings. sigh. My dad was a big football fan, loved the Bombers, loved Bud Grant, loved the Vikings. Old enough to have seen the Purple People Eaters play.
MLB - Twins - just a natural offshoot of the Vikings and proximity it seems. Kirby Puckett era was a lot of fun.
NBA - was a massive basketball fan growing up and have been a Celtics fan since the days of Russel/Cousy/Havlicek. That said, I cannot stand the NBA at this point. Respect the hell out of the talent and athleticism but it has been going the way of wrestling in favor of fan excitement. So much traveling, so much carry ball, so much bs drama. Thanks to visits in Seattle and when Minneapolis got the Wolves I got to see Erving, Bird, Magic, Jordan play. All from very terrible seats.
NCAA basketball - I can still watch this and grew up a fan of Louisville largely because of Darrell Griffith. I discovered him via a jumping contest they had between him and Garth Pischke. Garth was playing for the UofM volleyball team and the national team at the time.
Golf - I'll watch the majors but would rather play.
Wrassling - always enjoyed it but never serious about it. Fun entertainment.