I use one called the YTD Video Downloader, and it was downloaded from the CNET site:
www.downloads.com It is important to note that the software from the CNET site comes in a bundled installer, and all kinds of crap is sneakily presented during the install process, so that unless you are VERY vigilant, you will install some extra crap.
I have installed this software many many times, without problems, BUT I read every single screen presented in the install process. For this software, the default install options include you agreeing to install some extra software and to make Chrome your default, etc etc, so you have to do a custom install, and STILL you have to uncheck the boxes for the unwanted extra stuff.
Then, it STILL tries to trick you, by presenting a screen asking you to click Next to accept terms, but if you look at the top of the screen, it is for some additional extra software you do NOT want to install, so you have to decline in order to continue on to the actual install of the YTD Video Downloader software.
MUCH of the freeware out there these days has install processes such as above. The YTD Video Downloader itself is a fabulous program - you just have to be very vigilant during the install process, and the same is true for ANY freeware you install.
Bottom line - be careful with whatever you install. I DO recommend the above software, as long as you pay attention and read ALL before clicking on anything during install.
Bob Bone