Minitube is a native YouTube client. With it you can watch YouTube videos in a new way: you type a keyword, Minitube gives you an endless video stream. Minitube does not require the Flash Player.
Minitube is not about cloning the original Youtube web interface, it aims to create a new TV-like experience.
DARUKARU Not bad at all. Plays videos with much lower CPU usage than Flash in a browser. What it could really use is the ability to access subscriptions and to browse a user's videos and playlists. As it stands, multi-part videos are difficult to access because searching won't necessarily bring all the parts up in order. (Version 0.6)
TGV The application doesn't get very far on my MacBook. As soon as I have typed a few characters, it hangs indefinitely (in QThreadStorageData > QHostInfo > QWaitCondition, says Activity Monitory). (Version 0.5)