Mountain bikes - building, wrenching, experimenting, riding, etc. I use the ebike mostly for transportation - MTBs for fun and exercise. Grew up with essentially a bike park in my back yard, started riding 46 years ago, and lived through the evolution from BMX > early MTBs (still have one of the first) > ultra-modern canyon-slayers.
AV dork - mostly car audio. Also collect high-end vintage car audio. I got into it when I was 15, and have loved it all these years. Even turned it into a career.
Gamer - still have all my Playstations and a few other consoles, built probably a dozen gaming PC rigs over the years. Mostly flight-simming now on the PCs - also steadily/slowly studying for my private pilot if I can ever find enough money to fly on a regular basis.
Motorcycling (dual-sports). Taking a break from it until I move to a less-crowded spot, but miss it bigtime and am ready to dive back in.