A year ago my 39" TV went out.

I was so upset. But I replaced it with a $79 projector.

(Sure this required me to also buy a $25 Roku Express, a $60 Speaker tower, and a $35 screen, so I don't know if it counts as <$100)

Sports and movies have never looked so good.

If you don't count this, due to the cost of the accessories...then I have to say my 7" fire tablet. Got it for $25 Christmas season 2016. Disappointed in the sound quality, but I use the thing for so much streaming of sporting events while I'm at work, and reading comics on Hoopla, that I've gotten way more than my money's worth out of it. (And bought a second one since then for $40, because I got the first one filthy at work, and wanted one for around the house, and to take to the laundromat)