QuickTime/front row. How to watch .AVI?

I have a bunch of .AVI's and when I try to watch them with front row there is no picture. I assume I need a Codec or plug in. Where would I get it. Or if thats not the problem how do I make it work?

I would recommend two Quicktime codecs that should handle everything:

Flip4Mac's WMV plugin
Perian

Its not totaly what I was looking for but it works, I found a program that will import avi's into itunes so you can watch them with front row, if anyone needs something like that its called iSquint.