I was just looking through the 10 best Intranets of the 2009 report from Jakob Nielsen and 5 out of the Top Ten Intranets have been developed using SharePoint 2007.
In total, the 10 winners were built on 26 different products — substantially fewer than the 41 used in 2008 or the 49 used in 2007. Most impressively, fully half of the winning intranets used SharePoint, especially the recent MOSS platform (Microsoft Office SharePoint Server 2007). As the following chart shows, SharePoint use has grown dramatically in recent years. This is particularly impressive given that, from 2003–2006, the winning intranets didn't use earlier versions of SharePoint at all.
Check out the article here > http://www.useit.com/alertbox/intranet_design.html
Last year we had the Ministry of Transport New Zealand Intranet feature in the Top Ten.