ImTOO Download YouTube Video is a free video downloader. It can be used to download video files from YouTube.com and save them on your computer. The app is basically a web browser, so you can use it to watch videos as well as to download them. When you want to download a video from YouTube, all you have to do is to point at that video and click on the "Download" button when it becomes active.
In my testing, I downloaded the SD version of a video, and the whole process went smoothly. The download speed was on par with what I am used to seeing on other downloaders and it will depend on the speed of your Internet connection more than anything. The downloaded file played well on VLC and the quality was great.
This is a free downloader, but it has some limitations. For example, you can only download the SD versions of videos. You won't be able to download anything over 360p with this tool. Also, there is no support for video conversion. For that, you will have to either find yourself another free downloader that has those features or buy one of the downloaders by ImTOO. They have a nice $9.95 converter that works very well.