We all have used youtube to watch music videos and I know a few people that sit at their desks all day and have youtube playing in the background as their own personal jukebox.
Since January (I know I am a bit late here, but I was really busy) this has become a hell of a lot easier with youtube disco.
And I have to say that even though it is quite simple and not to fancy on the eye, it is one of the fastest and most accurate ways to find your music (videos) and related artists. It also gives you a little insight into the artist and you can add videos individually or just add them all.
Then all you have to do is mix it all up manually or press the shuffle button 
One thing I found very interesting is that the videos shown are not the official ones, but created by fans.
The only other site I have seen that would rival this is the Channel V site here. you can browse the whole site and never lose the music video you are watching.
Go ahead and try them both.
