If VirtualBSD is running on a Dual Core system or better and the host computer won't be doing a lot of work while the virtual machine is running, you may get a nice performance boost by enabling a second CPU.
Look toward the bottom of the VirtualBSD.vmx for the line which reads:
numvcpus = "1"
and change it to:
numvcpus = "2"
Save, exit the text editor and start VirtualBSD again. It should perform much better and, for instance, VLC will likely be able to play DVDs and videos smoothly.