There are many softwares to download online videos from YouTube to your computer for offline viewing. But most of them are bulky and really mess things around. When YouTube is updated, you need to download updated version of those softwares to work correctly. So this has been a big problem for sometime.
Other way to download YouTube videos is to connect to websites like keep-tube.com and download. This requires you to have Java installed on your computer.
> If you are using Firefox, first you need to install GreaseMonkey and then download Youtube Video Downloader Script.
> If you are using Google Chrome, Just download the Script and drag it on to your Chrome window to install.
> If you are using Safari, install GreaseKit first.
Now you are just one click away from downloading your favorite YouTube videos !! Goto your favorite YouTube video page, now you can see a download button next to share button below the video, click on that and download video in desired resolution !!
Happy Downloading :)