I wasn't sure which thread to put this but if anybody out there uses or are thinking of installing security cameras DivX usually has the least problems working because of all the codecs in it.
For the holiday they are offering the Pro Version for "free" for a limited time. I believe it normally costs $20. MPEG 2 won't be available in it but everything else will work.
http://www.divx.com/dff/index.php
PS make sure when you install you enter your email to recieve the serial number for the pro version.