Rated 5 out of 5 stars

Still the best and easiest to use.
Works perfecly with YouTube etc.
The little "fish" icon can be placed in various places using the extensions Options (and customize toolbar).
Unfortunately integration with Firefox's Down-them-all (DTA) extension is still broken (since FF44).
But you can still use Unplug to copy the link (from Unplug's dropdown download options). Then just click the + button in DTA Manager (this paste's the link into DTA).

This user has a previous review of this add-on.