I don't really have a favorite sport. I just ignore them most of the time and periodically jump into watching the playoffs if I'm bored. Sports that I'll watch in this way include basketball, hockey, pro American-style football, and soccer/football. Never watched martial arts competitions but hey, that might be interesting some time too. I'm so aloof in regards to sports that, while I have teams, I just choose the ones I like based on their team colors and logos. And if they lose I don't care because, hey, I don't follow regularly anyway.
As for participation, I want to get back into learning a martial art or a few and I used to be competent enough at soccer. None currently, though.
I use to be alright at some sports when I was younger, then I became more an indoor person and lost all my muscle.
I was pretty decent at badminton in HS, probably would still be decent if I picked it up. Swimming is something I'll always enjoy.