This is a great question. We have to pick an invention that does not depend on an installed infrastructure of other progressive technology. So, no cell phones, DVD writers, video cards etc. Or even newer cars and so forth which have tons of advanced digital components.
We should think of something that almost everyone has that was invented in the last 20 years and we all take for granted. But also meets the criteria of my first paragraph. Given that it can't be digital, it makes me want to look in my kitchen and bathroom for answers.
I'll be right back.
[time passes]
LED flashlight
Compact fluorescent light bulbs
Viagra [not actually in my bathroom, but I looked in my medicine cabinet and it made me think of medicine]
Splenda
Swiffer Wetjet
Brita and/or Pur water filters