Default Password Lists / Factory Defaults
Possibly the most complete list of default passwords I have ran across.
The Default Password List is a collection of accounts and passwords that are, by default, the initial passwords for specific accounts on a given computer system. Sometimes these passwords are installed out-of-box, sometimes they are automatically installed by software, and sometimes they are installed by consultants that are brought in to perform services. This list should be used as a resource for computer security consultants interested in testing the security configuration of equipment.
Here is the link: http://www.phenoelit-us.org/dpl/dpl.html
I realize this is not the only list, rather a list that I found useful.
More useful sites:
http://www.virus.org/default-password/view/M/1/
http://www.cirt.net/cgi-bin/passwd.pl
http://defaultpassword.com/