If you’re bought in to the Apple ecosystem, you can get a good HTPC by buying a 5+ year old Mac Mini from Craigslist. I’ve seen em for around $100, and unlike an AppleTV, you can run whatever additional Mac software you want. My 2010 is running great, recently upgraded to a SSD, and thanks to a kind soul here on HN pointing me to a link, can even run Mojave even though it’s technically unsupported.