Apple has a series of funny commercials comparing the Macintosh with a PC running Windows. They are very well written and presented. I recommend viewing them for the amusement value (view them here – but you need Quicktime).
Novell has produced a few short parodies of those adverts, they don’t have the same production quality but are well written and not nearly as cheesy as I had feared (view them here). Novell’s ads are in OGG and MP3 format.
Update: A comment pointed me to this site which has other parodies of the Mac adverts. There is quite a bit of bad language and the parodies will offend some people in several ways. But they are amusing and do make some interesting points.