I tried to find the best YouTube/Vimeo downloader app recently and after trying at least half a dozen this is what I settled on.
Why do I like it? Well unlike some downloaders it doesn't try to be a half-baked web browser! I don't want a video downloader to be a browser without all the security and ad-blocking features I normally enforce. Secondly, this app had a nice, simple and easy to use UI. Simply paste the link to a video or channel and you're away! Thirdly it had a decent amount of configurability so I could decide which video quality I wanted and how many download streams and save this in preferences and not have to specify each time. Fourthly it works for Vimeo as well as YouTube. I love Vimeo so this was another key feature I wanted. Fifthly it has YouTube playlist downloading so you can download an entire playlist as easily as a single video. It's so easy and works flawlessly. Finally and perhaps most importantly the app was reliable and fast with the videos I tested.
While some of the other apps had some of these features, no other app I tried had them all. Not wanting the browser rules out a fair few and good reliable playlist downloading a few more. The rest are just icing on the cake.
Yes this app isn't free (MacUpdate is incorrect) but the best software often isn't. Even still they have a generous free version without popups or otherwise intrusive and over-the-top advertising. I feel like I'm getting what I paid for in this app so I'm a happy customer. Downloading a high quality tutorial series of 30 videos and this app has already paid for itself by way of convenience and time saved.