I’ve tried a couple of setups including LibreELEC on a Raspberry Pi and self-compiled Plasma Bigscreen on x86, but my current and favourite setup is just stock Plasma with some configuration.

• First, get yourself a cheap “air mouse” remote. I have a WeChip brand one, works like a remote control crossed with a Wiimote, with a little keyboard on the back. There’s a handful of different brands, a quick search on Amazon will show a variety of different types. Having a regular wireless keyboard + mouse (like those cheap Logitech ones) is helpful if you want to do more complicated things than watch media.
• Starting with a stock Plasma desktop, I turn up the desktop icon size and make the bar taller, so it’s easier to click on things accurately. There’s also an alternative launcher menu in Plasma that goes fullscreen (instead of the start menu-style default).
• Next I make desktop shortcuts for the main apps/services I use. For Jellyfin I make a shortcut to the client, for commercial streaming services I make URL shortcuts that open in the default browser. I also like to set the desktop wallpaper to a solid colour.
• In Plasma’s system settings, make a window rule for the default browser to make it open in fullscreen. If you need, you can do the same for other programs (my Jellyfin client has its own setting, so this isn’t needed).

I use an x86 machine for this to avoid having to deal with getting widevine working for browser streaming. I use Librewolf as my browser and it works well. I know with some commercial streaming services there are video quality restrictions when watching through a browser on Linux, but that can’t be avoided without using a locked-down platform anyway. These days I’m mostly using Jellyfin and it works great.

I used to really want the “polished” HTPC UI, but over time (and after yet another botched Ubuntu version upgrade), I realised that this setup gets you 90% there with way less hassle, and the last 10% is just aesthetics. Using a common, well-supported desktop environment makes troubleshooting a lot easier too.

Pssst, take these: .,

Honestly, none that are all that great. I tried Kodi in various forms, LibreElec, OSMC, MythTV, Steam Big Picture, and KDE TV (or whatever its called), but you’re just never going to get a great experience with stuff like Netflix and YouTube on Linux.

In the end, I bought myself an Nvidia Shield, switched out the launcher for one without ads, installed Smart Tube Next for ad-free YouTube, and I couldn’t be happier with the results. I’ve got my apps for Nebula and Dropout. I’ve got Kodi and Jellyfin for my home library. It has barely any power consumption, it boots fast, it runs a huge variety of emulators, the included remote works great (plus there’s a remote app for your phone that controls the entire system), and the wife acceptance factor is exceptional.

I’m really big on self-hosting and building all my own stuff; I use lots of repurposed hardware salvaged from companies I and my friends work at and I try to avoid off the shelf products. But I’m genuinely kicking myself for not buying a Shield sooner. It really is the best TV solution for a self hoster.

https://plasma-bigscreen.org/ from KDE? I’m not sure if they’ve replaced that since. Wikipedia says it’s unmaintained. Depending on your use-case, you might want to have a look at Emulationstation, Steam Big Picture and Kodi Plugins, as well.

I went down this rabbit hole about a year ago, and didn’t have much luck. In the end, the best results I was able to get were from Steam’s Big Picture Mode on a Windows device, mostly launching Firefox (might have been Chrome?) with different launch arguments to immitate a smart TV.

Most available software either doesn’t support Linux well, doesn’t support streaming services and outside software, or doesn’t support non-kb&m input methods. You can get two, but never all three. You could try SteamOS, now that its out, but unfortunately my hopes wouldn’t be high for it to have all the apps you needs functioning.

Buy an LG Smart TV and use the WebOS version of Jellyfin. That’s the best I’ve achieved.

There are a few things about Kodi that might help:

1. There are themes thay completely change the UI, so it doesn’t have to be outdated. I use Arctic: Zephyr – Reloaded and it is much better, though I did change the noises to something else.
2. The Jellyfin plugin works pretty seamlessly if you set up the UI correctly. I only use Kodi for Jellyfin and it acts as if it’s all local files, other than the occasional syncing notice.

However, I feel you on Netflix, YouTube, etc. - it is not ideal. I ended up either logging into a separate partition or moving to a Chromecast for those things. I’d love an all-in-one solution but I haven’t managed to find one that I’d be happy with.

MythTV - as others have already mentioned. It’s designed to work with the 10’ interface

Even records TV programs (presuming you have tuner hardware of course) - which I don’t think the others can do?

We don’t stream Netflix, but we do watch other various streams (ie BBC iPlayer), yoochoob, etc - all works fine, inc… video files from various sources, and music…

We use it with a Logitech K400 wireless keyboard and it works great for us.

I have played with a more traditional looking TV wand remote in the past, but you still need a keyboard to type in program websites, names, etc. so the K400 became our defacto remote.

MythTV used to come with Ubuntu as Mythbuntu back in the day, but most of the pre-installed distros have fallen away, so you’d need to pick a distro and install it yourself.

It’s a very mature application, so you won’t need to keep updating every time you want to watch anything.

Not a fully fledged DE but might be enough for your usecase: Flex-Launcher

What about android TV?

https://konstakang.com/devices/rpi4/LineageOS20-ATV/

Maybe this might be something to consider

MythTV is the OG.

libreELEC, but that’s just a distribution shipping kodi.

you might be able to utilize steam big picture/steamOS with different browser shortcuts and applications added as non-steam games to open streaming services in kiosk mode or other mediaplayers , that way you’d have good controller support, if you create control schemes for various things.

Steam Big Picture Mode allows you to install non steam apps.

Don’t have any recent experience to help you, but your question reminded me of Boxee and I had a little flash back to a simpler time.