Probably either my Olympus OM-1 or my Minolta SR-T 201. Both still work (the Olympus just needs some cleaning and maintenance)
Donkey Kong Game & Watch (1982)
1983 Lenco LRP 5450 DD record player &
1998 Yamaha RX-496 RDS stereo receiver
My stepfather got them for us 2nd hand for a joint present. Quite a decent system!
Not a real audiophile, but it works well and we enjoy it.
I also made a Google Home kind of thing out of it using an ESP32S3 that uses ESPHome, Home Assistant, and Music Assistant to make it a Spotify connect node to play Spotify through it, control it with an IR blaster, and use Voice Assistant with it if I am not too far (it has a single mema mic)
I have an electric singer sewing machine from 1964 and another one from around 1950. Amazing how well they work.
Extremely old singer sewing machine gang unite
I still have a CRT from the early 90s and all my old video game consoles.
Original Gameboy.
Still works.
I have a CRT from 1995. Aside from that, probably my dad’s turntable which has unofficially become mine, or the Yamaha electric keyboard
My Nintendo dsi. Since 2009
Either the wood-grain radio with clock or a 1970s bubble-LED calculator
I have a Milton Bradley Microvision from around 1979, the first handheld game system that used cartridges. I have the block breaker game, it still works but I think some components are wearing out as the game speed feels way too fast. Thing takes 2 9V batteries!
Sega Megadrive from about 1989.
An originally original gameboy. Still worked until about 2 years ago. I assume there’s just a little battery or a capacitor that needs replacing, but I haven’t had the time to look into it.
Casio f-91w watch. Its like 6 years old now, so the battery only has like 4 more years left.
Not a full electronic per se, but I do have a heatsink from an old second gen IBM memory module.
A Nintendo64 with several game cartridges. It’s a little flaky, but it still works for the most part.
