Finally a really good video downloader!
Nowadays it is hard to find a reputable and well-functioning video downloader for YouTube as most of them are flooded with advertisements and redirect you to rogue sites.
But after a bit of searching I found one that I've been using with satisfaction for months.
The advertising is not intrusive and can optionally be removed with a one-time purchase.
I especially like the "Smart Mode" function, with which you can switch between different download presets!
The standard version is free, so if you need a video downloader, download it!
There is also a good solution for audio downloads and Instagram images, which you can find here: