From Optflux
If you’d rather do without the hassle of downloading a certain download youtube videos to download your favorite YouTube video, you can always use an online tool. Though there are several web-based download platforms for YouTube, GetanyVideo is our current favorite. It’s neat and fast and won’t have you ever clicking through pages which spawn popups or any other intrusive ads.
1: Get the YouTube video you would like to download and copy its URL in the address bar near the top of your browser window.
Step 2: Visit the GetanyVideo webpage.
Step 3: Paste it in the bar that reads “Enter the video's link...”
Step 4: Select your selected video format and click the respective blue “Download” button around the right-hand side.