You could download it with ClipGrab! Works very well for me, it's how I got the music tracks I then assembled together. It just downloads the videos as they're stored on the servers, so you're seeing the same level of quality - no re-encoding involved.
EDIT: Disregard this, I misread the page. ~~That's just your subscriptions, not the video.~~ You may need to use a video downloading tool like ClipGrab, unless you can get a bulk downloading tool like DownThemAll working with the "Download MP4" link on each video dropdown here.
I've used ClipGrab for batches of YouTube videos. It seems to work well and allows you to select which resolution you want. But, the one limitation is that it doesn't really do "bulk" lists or that kind of thing.
---> http://clipgrab.org/
It is free and easy, so if you don't have more than 10-20 or so videos, it might be worth a shot to just copy their links one-by-one. But, if you have some larger number to do, then need some other tool.
I've been using clipgrab. Works perfectly for downloading youtube videos and converting it, including mp3. It can also be used for downloading videos off of a lot of other websites.
The best downloaders Ive used to date is clipgrab (http://clipgrab.org). It monitors the clipboard and downloads from any site.
If you have any hassles, PM me. Ive been doing Linux support for years.
I don't have a specific site to download songs.
However if you like a specific song on Youtube, you can download that video and convert it in MP3 format with ClipGrab. It's quick, easy, virus-free, and great if you want to download single songs. I personally use this and it is amazing. I recommend you try it.
How to use ClipGrab
EDIT: Added instructions just in case there is any confusion