If you feel safe using a file-sharing (P2P) network, meaning you have good anti-virus protection, you could try either Ares or Limewire, though Ares is much faster and more reliable...then there'* Bearshare, Morpheus, etc. (Just Google the names to find the downloads for the programs)
I don't promote doing this, because I'm not sure on the legality of the matter, but since it'* not actual MUSIC or MOVIES you're downloading, it'* a video that they've probably shown on MTV, VH1, etc, I don't think there would be a problem with it.
I'm sure there'* other methods of getting your hands on the music videos, maybe someone else can chime in
Also, have you checked out Youtube?