Trying to make a video player that constantly shuffles and plays video files from a hard drive

Hey everyone! I am trying to make a "substitute cable box" with a raspberry pi. I would like to create a raspberry pi that is constantly playing videos in a folder on a flash drive connected to the pi in a random order. My idea is to dump all of the various TV show files that I enjoy re-watching onto this folder. This way, all I have to do is turn on my tv and tune into the Pi already running and playing a random selection of files.

I figure if I set the pi to auto-run a video playing program on boot (XBMC or VLC), but has anyone figured out a way to automatically play a file on boot? Or a way to shuffle a video playlist?

Thanks for any help!