I've used a few different downloaders over the years, but this one tops them all.
110/100
*added 26/4/2019:
Once again this addon has been updated quickly to accommodate youtube's code changes. Dishita works very hard to keep this working, well done. I will make another donation today !

I have tried quite a few video downloaders. This one is just the best of all.

It is SO extremely refreshing, especially in "today's cut-throat world of PROFITS at ANY COST" to have brilliant computer coders such as "Dishita" willing to provide their time and skills TOTALLY FREE of charge for we YouTube users!
Without such generous and giving people such as Dishita, people like myself wouldn't even be able to USE YouTube AT ALL, because my ISP and internet connection are so lame and slow I cannot even Stream YouTube videos directly from their site in real time, instead I have to download the videos first to be able to watch them "lag free" at a later time.
Therefore my eternal thanks and gratitude go out to you Dashita, I have gladly made a donation for you to keep up your great, (and in my case), ESSENTIAL WORK, so I am able to use YouTube and even create my own "How to" video library.
Many, MANY THANKS "Dishita"!
"Bars450" aka "Cuerammer"

Program usually works without problems and is easy to use.

I've used different downloaders over the years and I always come back to Downloader Express. It simply works when others fail.

I love this program! It is the simplest way to download videos

What do you get the man who has everything? This add on. Works effectively and efficiently. So impressed I bought the paid version and about to contribute more. And lest I forget, support is amazing. So where do I select six stars?

Love Easy Youtube Video Downloader for its ease of use, fast downloads and practicality . Happy to donate a small amount to support this service and for the personal support they provide if needed. Thanks.

It works great and now it even supports the latest YouTube format. Really useful extension!

OK, I know that this is not the place for reporting bugs, but please, since the support is closed unless you are a paid member, this in the only place...

The new version (10.2) works very well (until now) if you click on a video that opens in the same tab. If you click on a video opening a new tab, two buttons appear instead of one, and both buttons are completely unresponsive.

Best addon of this genre, anyway.

This is the best downloader without fail. It's easy to use and for me has worked every time. The drop down menu makes it easy to see the options for the filetype you want to download. This guy is genuine and enthusiastic so if you use this then buy him a coffee.. i'm sure every little bit helps and it's worth a few bucks if you want the ability to quickly and reliably download from youtube. I have my FF browser loaded with security plugins/add-ons etc and it still works a treat.

Very easy to use and super useful for me since my internet is not so good here now i have videos and tutorials to watch and learn while working.

The developer responds quickly to bug reports in reviews, although he complains that users "jump quickly" to post negative reviews "as soon as a bug appears."

Well, how would a new user know that a bug just appeared? Furthermore, the developer's support page says that the support system is shut off, except for paying "pro" customers. That leaves reviews as our only means of communicating problems.

And there are still problems. The developer quickly fixed an issue where the "download as" buttons did nothing (referred to in the "fixed" message below)... but the plug-in still does not appear to work. I did in fact upgrade to the "pro" version so I could download 1080p material, but an attempt to do so simply evokes a "dispatched for processing" message. After 45 minutes, I still have no sign of the video being downloaded.

The publisher's user forum ( https://youtube-downloader.uservoice.com/forums/225282-general ) is useless. It lets you type out an entire question (or "idea") but the "Post idea" button does nothing. Don't waste your time.

By far the easiest and most user friendly downloader I've every used. TImely and easy updates. Great service. Buy them (him) a coffee.

Has consistently been the best of the downloaders out there. Been using it for years and have been happy with it.

This is an excellent add-on. It does exactly what it supposed to in a user-friendly way. I have used it to create a huge collection of videos to view offline, particularly useful to me as my internet service is unreliable. Well worth a donation, and well worth upgrading to Pro is you need the extra functionality.

By far the easiest and most user friendly downloader I've every used. TImely and easy updates. Great service. Buy them (him) a coffee.

I've been using this addon for close to 3 years and am very happy with it. I originally used the free version and then upgraded by donating a small amount which then gives you extra download options like HD and mp3. I will donate again once the changes are made for the new look youtube as I'm sure this is a lot of work for the developer. Thanks

Extremely easy to use, updates automatically, and covers a huge variety of download capabilities! Very much appreciate this outstanding addon which I use daily!

no 1 youtube downloader and doesn't have support for new youtube layout: "WARNING : 'Easy Youtube Video Downloader' is not compatible with the experimental YouTube Material Layout
which is under BETA testing".

Can't use mp3 downloading unless I go pro.

I think it works very well, fast download with great quality

Have been using this for few years and love it! Very easy to use and gives you several options for file type and size to download. I had tried several other downloaders and they can't hold candle to this one!

Meine WebExtension zum Herunterladen von youtube Videos!!
Für $10 gibt es eine Proversion, für das 1080p Format. Ich finde dieses bisschen Geld gut angelegt.