So I started here:
http://ignitemotion.com/ Which is a great site for free-to-use, royalty free animated video backgrounds.
And I found a link to here:
http://www.anistock.com/Okay, so you have to pay for them, yes. BUT! If you sign up for the 25 download plan, it's $25 to download 25 clips, whenever you want (within a year of signing up).
And it's all royalty free.
There's a TON of fantastic clips on there, and if you sign up for the plan I did, they're just $1 to download medium quality 480x360 versions of the videos.
Quicktime, Mobile, or Flash.
It actually only came to ~$23.50 for me. So I'm getting each clip for less than $1.
Anyway, browse around, and you'll see what I mean. If you have a program like Final Cut or Arkaos, you can do amazing things with this material, and I can only imagine the applications for video game making.