The Mac has better software.
Any new Mac you buy comes with software (iMovie, iDVD) to grab movies from a digital source such as a mini-dv camera and edit it, add special effects and titles, and create your own DVD movie. All in a very user-friendly way.
There is higher end stuff such as Final Cut Pro, DVD Studio Pro, etc. which appeals to the professional film-makers (even Hollywood blockbusters).
Also there is software (iPhoto) to grab images from digital cameras, crop/resize/retouch them, organise them into albums, create slideshows, print them, publish them on the Web, order prints, burn them to a Photo-CD or a normal Data-CD, even burn them to DVD as a movie. I know several professional photographers who use Macs exclusively.
The iLife software is all integrated so you can import and export directly from iMovie to iDVD or iPhoto to iDVD etc.
And of course the Software is all free with the Mac, so you can start creating from day one.
On PC, to get a suite of software as extensive and full of features as the iLife package would cost hundreds (maybe thousands) of pounds.
Macs have taken over from Amiga as computer of choice for the creative professional. Until Amiga gets some cheap / free software to match the Mac offerings, I don't think this will change.
