From Jakob Nielsen, this summary on his choices for the Ten Best Intranets of 2005 (6 from the US, and one from each of the following countries: Spain, UK, The Netherlands, and Sweden). The winners used a range of platforms, interfaces (including wikis), applications and software. It would appear the message is that customized features and targeted services are hallmarks of success. The full report (235 pages, PDF), is available for a fee.