I haven’t tried enough of the options to tell you that.
Personally I use Smooth Video Project anyway, so it’s conveniet to also use their SVPtube tool. It just wraps youtube-dl and provides a little GUI for it.
There are a bunch of other GUIs for youtube-dl too
The fundamental issue is that he’s looking for someone to provide a free service instead of for someone to provide free software.
The latter happens so much more often because it doesn’t create ongoing costs for the developer.
What’s the best free software?
Yt-dlp
I haven’t tried enough of the options to tell you that.
Personally I use Smooth Video Project anyway, so it’s conveniet to also use their SVPtube tool. It just wraps youtube-dl and provides a little GUI for it.
There are a bunch of other GUIs for youtube-dl too