Mac Pick: Downie
Andy Ihnatko's pick of the week on MacBreak Weekly 503 is the Downie video downloader by Charlie Monroe. This works on over 1,000 different sites that have embedded video. All you need to do is paste the URL into the Downie window, and it will start downloading the best quality version of that video. There's even a browser plugin so you can simply click the Downie button and it will add the video to the download queue.
Downie has plenty of settings and options, including postprocessing to extract just the audio from a video or get the video in a specific format. It also supports 4K video on YouTube. Downie is $19.99 and has a free trial.