A few, a silver Pikachu Gameboy color, some synthesizers from the 1980’s, a unique guitar that I’ve only been able to find documentation of 1 other one online (Ibanez Nitro full wood body finish - it’s certainly a custom). And I think the last pride and joy is my Sony MDR-V600’s.
Anybody remember Cube World? Those little electronic cubes that you could magnetically attach to others and they could interact? Got a set of those too.
The music stuff is the oldest but it’s mostly second hand so it’s harder to claim. The headphones were a gift and new back then though, so they’re for sure, same with the Gameboy color and Cube World. Heh :)