The Nvidia Shield is still the best option for this. I’ve tried all kinds of homebrew solutions and always had headaches. In the two years I’ve had my Shield, I’ve never had a problem. Smart Tube Next lets me cast YouTube without ads, Kodi/Jellyfin gives me all my media library, plus I’ve got official apps for Nebula, Dropout and Spotify. Custom launcher removes what little amount of ads there were (and that was unobtrusive background banner stuff even at its worst). Plus the pro version can handle some pretty powerful emulators.