I've heard of piped due to the piped-link bot, but I am curious about others.
GrayJay just came out into the testing phase. It not only supportsYouTubee but also Nebula, Odysee, Twitch, PeerTube and a few others with more to come. Works great so far. grayjay.app. Built by Futo, a nonprofit company which Louis Rossmann works for. His video here
Looks like a good option, unfortunately it would not run for me on an Android emulator in Windows. (LDPlayer 5)
Web
For the web, there is Piped (github.com/teampiped/piped) and Invidious (invidious.io)
NOTE: Only Piped proxies your videos, which means invidious allows connections directly to Google to load the video.
Android
On Android, there's NewPipe and LibreTube which are well known by now.
NOTE: LibreTube uses Piped to preserve privacy and (somewhat) anonymity when watching, thus you'll need to select some piped instance with it.
iOS
On iOS, there's the web frontends and Yattee (github.com/yattee/yattee).
NOTE: Yattee is on the AppStore, but without any sources/instances by default. Look for "instances" in the settings and add a Piped API URL, like
https://pipedapi.kavin.rocks
to watch videos from YouTube with Piped+Yattee.Desktop
On Desktop, there is all the web clients as well as FreeTube (freetubeapp.io).
NOTE: FreeTube has an option to proxy everything or just the videos through Invidious to preserve privacy. It is recommended to enable this.
SmartTube is excellent on our NVidia Shield. Not sure what other platforms it works on.
Seconding SmartTube on android TV. No ads, can automatically skip all sorts of content in videos (spoken ads, self-promotion, introduction segments, etc. etc. etc.) I dread the day it stops working.
Best overall SmartTube for Android TV and NewPipe with SponsorBlock for Android.
Been using revanced for a while - had no idea there were this many alternatives. I like revanced though, especially with stube on Google tv.
Invidious. If you look up invidious instances you can find plenty of them and choose one that’s in your country so it’s nice and fast. Sometimes they take an extra second to load but there are no ads so it’s worth it
On android i like newpipe + sponsorblock and clipious. Id use clipious all the time but it sometimes doesnt play and then i fall back on newpipe. Newpipe has downloading too.
I dont use youtube much on desktop but when i do i use invidious
Oh and i use smartubenext on android tv