For the multimedia section, i would be more likely to recommend vlc. The dependencies that come along with it provide codecs for most file types.

A section on storage might be handy too:
mount – show all mounted filesystems
sudo umount /dev/sdx ->> unmount filesytem on device sdx
sudo fdisk -l -> list all volume devices
blkid -> list filesystems available on all storage devices
sudo mount -t ntfs /dev/sdx /mountpoint -> mount the NTFS filesystem on device sdx at /mountpoint

Another one I use often is dd, though it doesn’t quite fit on a cheatsheet. It reads info from a device block by block, without the need to interpret the data or mount the filesystem. You could use it to back up or wipe out whole disks, back up MBRs, and more. I use it to rotate images onto a flash drive; There’s an image of the ultimate boot cd, a dos boot disk full of BIOS ROMs, a linux live distro, and more. Usage goes like this:

dd if=/dev/sdx of=bootdiags.iso -> makes an iso image of the device sdx. Note that the partitioning scheme and MBR will remain intact.
dd if=fedora-live.iso of=/dev/sdx -> Now that the image is backed up, I can re-image my thumb drive with something more appropriate to the task at hand. It can be invaluable in the field.