A few years ago in Amsterdam , The Netherlands a construction company had to dig a tunnel through a former canal. The canal existed for few hundreds of years and was only a decade ago filled and a road was build on top of it. They found about 700.000 artifacts from the middle-ages till modern times. Speer arrows, swords, guns, money, credit cards, music cassettes, smoke pipes etc. I believe there is a exposition dedicated to those findings. Very interesting.

Probably objects that make you imagine about what day-to-day living was like in the past.

If VR becomes widespread, perhaps the first VR headset. Or perhaps niche, quaint items with great craftsmanship (no longer used at all in the future), like a high-quality metal mechanical pencil, fountain pen, or ballpoint pen.

Early commercial spacecraft (SpaceX) would also be a certainty, as the expansion of humanity across space is near-guaranteed (as long as humanity doesn't destroy itself). Perhaps also today's fashion (thinking of fashion museums).

Space archaeology will be really interesting. So many satellites and other things to be found scattered around Earth, the solar system, and beyond.

Someone some day will perhaps dig up a completely buried Mars lander under windblown sand, or send their fast vehicle out to capture images of the Voyager probes.

A still working Apple II that was forgotten in a bunker.

Anything newer would probably refuse to boot up due to expired certificates and missing drm servers.

They'd have to replace the capacitors, but it's perhaps possible.

Fidget spinners

Bitcoins ;)