Well, I've got almost 50 GB of pictures+music+videos. So it doesn't sound out of the ordinary.
My iTunes library is 28.83 GB (all legal,) my iPhoto library is 17.3 GB. My 'Movies' folder is 1 GB, and that's WITHOUT any iMovie or iDVD projects (on external hard drives,) or, uh, 'location-shifted video'... (Legally owned, but the process of location shifting a DVD is apparently of dubious legality in the U.S.)
This is on my MacBook Pro with a 100 GB drive. I also have a 6 GB Boot Camp partition, and a 5 GB Parallels disk image, so 11 GB of 'Windows'.
1 GB of Mail, and 1 GB of documents round out my mess. (I have mono-localized, but I have all my themes, as I actually use iMovie and iDVD...)