Rugby Union used to be my #1 sport to watch and play. But I'm past it now, tried playing again a couple years back and wrecked my knee. To watch I've really fallen out of love with the game, it's sad seeing what's happened with the English Premiership, and the six nations needs changing.
At least my team (Harlequins) is in that sweet spot of being good to watch, decent enough to occasionally win stuff, but not dominant and boring, so I still watch.
I started watching club football more about 7-8 years ago mainly as something to talk to the in-laws about (she's from Manc and the whole family are rabid united supporters) so I kinda fell into it as well. I spend most weekend days out climbing so the later kick offs and weekday games are better suited to my schedule, and obviously there's no shortage of games to watch.
Always been into test cricket, nothing better than sunny summers listening to TMS. T20 has evolved into a great sport. The one day game is just a bit **** in comparison.
UFC is ace. Not giving boxing anymore money, it's a farce these days.
I will watch pretty much any sport though. I have basically zero interest in TV and Film these days, the TV only goes on for sport. I quite like MLB and NFL occasionally.