Well this looks like a good place for me to just bang out everything I know:
Browser
Ublock Origin - Ad blocking browser extension for both chrome and firefox for using the official site
Piped - Alternative frontend - I selfhost my own one, it works really well
Invidious - Alternative frontend
Poke - Dunno thought it was cute
Android TV/Fire TV etc
SmartTube - The best youtube tv app.
Android
LibreTube - I have tried this one and liked it. Piped API.
NewPipe - Joins multiple services together (Youtube, Peertube, Soundcloud etc). Not related to Piped.
Tubular - NewPipe fork with Sponsorblock.
Vibe You - Music focused. PIped API.
Harmony Music - Music focused. Piped API. Also has Windows and Linux clients.
Android/iOS/MacOS/Linux/Windows
Spotube - Combines Youtube/Piped sources to use with your Spotify account. Most of the benefits of premium Spotify for free. Bespoke clients for each platform.
Linux/Windows/MacOS
FreeTube - Private frontend for your desktop.
iOS/MacOS/Apple TV(TV OS)
Yattee - Privacy oriented video player for iOS, tvOS and macOS. Uses Piped API.
Linux/Linux Phone
AudioTube - Youtube Music
Not an exhaustive list but should cover everyones bases. Expect bits of jank as youtube flounders around trying to break things. I would just ask that people donate to both the people they watch and any open source projects they use if possible.
Apple TV, sadly. No good solution for that yet.
Check out Yattee above.