MediaTube is a program for Mac that works like a browser for the YouTube website, the well-known video sharing website. The difference between using your default browser and working with MediaTube is the fact that the latter doesn't require Flash player to display videos. Hence, it uses less CPU resources when playing YouTube clips.
The app features a straightforward interface, allows you to choose the quality of the YouTube clips (from the main menu of the app), and comes with individual sound control options. I like that you can use hotkeys to play the next or previous YouTube clips and watch videos in fullscreen mode.
What's more, this program also provides you with an integrated search tool that helps you easily and quickly find the YouTube clips you wish to watch. MediaTube keeps a history log with all videos you played so far; you can access them by going to File -> Open Recent menu.
The one feature I would love to see in a next version is the ability to log in to your YouTube account from the app's interface. For the moment, you don't have access to this type of option.
Briefly, MediaTube is a capable streaming utility that lets you watch YouTube clips directly from your desktop. I'd say it's definitely worth installing it on your Mac, especially since it comes without a price.