This project provides a collection of free SharePoint Foundation & SharePoint Server MasterPages.
This includes not only the MasterPages but the overiding CSS.
Free version download: Free SharePoint 2010 MasterPages
SharePoint 2010 Sample Master Page 1
SharePoint 2010 Sample Master Page 2
There are three downloads available at the moment;
FreeSPMPComplete which contains all the available MasterPages and CSS
OrangeWebsite which contains the files for the Orange Website which can be seen here http://sharepoint.weknownothing.co.uk/ExampleWebsite/SitePages/Home.aspx
BlueWebsite which contains the files for the Blue Website which can be seen here http://sharepoint.weknownothing.co.uk/ExampleWebsite2/SitePages/Home.aspx