Using a terminal you may wish to give a chance to youtube-dl which can be easily installed by dropping sudo apt-get install youtube-dl and its usage is quite easy: simply copy the youtube url and add it in the terminal just after youtube-dl as shown in the next example:
youtube-dl http://www.youtube.com/watch?v=yQEaXAoB6Ck
This code will download Baltimora Chinese Restaurant video.
This will resut in the flv video to be downloaded in the folder where the terminal resides at the very moment that you start downloading, so make sure you first change directory to your videos folder.
Another excellent option is via GUI, by using Mobile Media Converter by MikSoft
And or JDownloader. JDownloader will also allow you to choose which video format you want to donload based on the available formats in youtube, which may include but not limited to: mp4, flv, ogv, mp3 and a few other.
Good luck!
Shortcuts
If all of the videos are in the same playlist or the same channel, you can save time by using the following shortcuts.
Playlist
youtube-dl -f FORMAT -ciw -o "%(title)s.%(ext)s" -v <url-of-playlist>
...where <url-of-playlist> is replaced by the URL of the playlist and replace FORMAT with any available video format, for example 18. You can use the -F option to see all valid formats like this:
youtube-dl -F 'http://www.youtube.com/some-alphanumeric-string'
Download part of a playlist from start of batch to end of batch
youtube-dl -f FORMAT -ci --playlist-start NUMBER --playlist-end NUMBER <url-of-playlist>
...where <url-of-playlist> is replaced by the URL of the playlist, replace FORMAT with any available video format, for example 18, and NUMBER is the number of the video in the playlist to start/end downloading at.
Channel
youtube-dl -f FORMAT -ciw -o "%(title)s.%(ext)s" -v <url-of-channel>
...where <url-of-channel> is replaced by the URL of the channel and replace FORMAT with any available video format, for example 18.
Videos not in the same playlist or channel
First create a batch file which is a text file containing a list of URLs of videos from YouTube that you want to download. The URLs should be arranged in a list having only one URL and nothing else on each line, with a new line for each URL in the list. Save the batch file with a name that is easy to remember like batch-file.txt. If the multiple files are all on the same playlist, channel or user webpage in YouTube, you can generate a text file with a list that has all the links on that page by running the following command:
sudo apt install jq
youtube-dl -j --flat-playlist "https://<yourYoutubeWebpage>" | jq -r '.id' | sed 's_^_https://youtu.be/_' > batch-file.txt
From the terminal run:
youtube-dl -ct --simulate --batch-file='/path/to/batch-file.txt'
This is the basic command, however you also need to add the formats of the videos that you want to download or else you may find yourself downloading videos with formats that you didn't want. So first simulate your download to see if the format you want is available:
youtube-dl -ct -f 34 --simulate 'http://www.youtube.com/some-alphanumeric-string'
If the video format is not available you will get an error message that says: requested format not available. If the video format is available you will not get any error message when you use the --simulate option. You can also add the -F option to see all valid formats like this:
youtube-dl -F 'http://www.youtube.com/some-alphanumeric-string'
In the third command I have used the common flv 360p video format:
-f 34. You might prefer to try the flv 480p video format by using -f 35. So after you have added the video format that you want to the command, the command becomes something like this:
youtube-dl -ciw -o "%(title)s.%(ext)s" --batch-file='/path/to/batch-file.txt'
Notes:
I didn't add the --simulate option to the last command, so this command would be executed for real.
Best Answer
How about: