Screw the running water and antibiotics. I don't need no machinery or amenities, give me cheese!

Computers are cool though

The Tamagotchi - for obvious reasons.

Written language. It lets us speak to people across time.

I don't know if this counts, but I'd say the Enlightenment. It was a discovery in that we discovered a new way to interpret the world.

I think there is kind of a glass ceiling when you talk about fire, plumbing, electricity and so on. Each one was a necessary stepping stone to get us where we are, but without any one of them, we wouldn't be here.

The Enlightenment gave us a brand new sense of autonomy as a species, which in turn has given us a greater amount of control over "Destiny."

Not the just important invention, but definitely the best invention: plumbing.

Y'all try going a week without running water and wiping with leaves or newspaper and you'll quickly see that while other things are definitely important, plumbing is the best to have

Cordage/string. Way more useful than fire and arguably predates it.

You're looking at it.

Microwave. Being able to heat up a hot pocket in just minutes is legendary.

I believe argiculture and trade were massive parts of history

Electricity

Copper. Because without copper, most of the named things wouldn't be possible to create!

Central air

The wheel and the derivatives of the circular shape in general; they powered all human innovations from abstract mathematics to real life applications and everything in between.

Medicine. Would be right fucked without it

Literature, Writing, Written Word. If we couldn't document and share ideas, we'd be nowhere.

The ability to shape steel. Sounds basic but blacksmiths make the tools for everything else.

The printing press. It allowed us for the first time to share knowledge at a scale we only dreamed of.

Spray cheese

The time machine.

Air conditioning

Irrigation. But Iron Working and Celestial Navigation are good shouts too.