There's a long list of sites that use Nucleus at the Nucleus web site: http://www.nucleuscms.org/sites.php. This area on the Wiki is for regular users to describe their sites in a bit more detail. Add whatever you'd like: main purpose (personal blog, multi-author blog, news site, community site.); plug-ins used; any minor modifications (for example if you don't use the standard category list - what you're doing instead and why); or anything else you'd like to share.
kgblog - Personal weblog with stuff that I'm interested in. Mainly in German, but some entries in English. (I stay with Nucleus CMS, regardless I like the new website from Xiffy. )
Leng-Lui.info - The personal weblog of LengL. Contains personal weblog, an online portfolio of artwork and writings, personal thoughts on a variety of subjects, amusing reads and other random sections.
pocket-expert.de - German language blog about Windows CE, Pocket PCs and Windows Mobile 2003 devices.
RandomStuffPlanet blogs RandomStuffPlanet hosts multiple blogs including the popular RandomThoughts Blog. It uses the newest version of Nucleus, a heavily modified version of Stanch for the skin, and some miscellaneous plugins.
TeRanEX Weblog - The personal weblog of TeRanEX about stuff that interests me, like Internet, Mozilla, Firefox, Thunderbird, and weblogs, webdesign and internet/www in general, Open Source/Free Software and Nucleus CMS, but also sometimes about daily stuff like travel and humor!
The Manic School Bus The Random Ramblings of a Manic Bus Driver plus recent news about school buses.
Tale of the Chirrupling - Weblog which talks about anything considered interesting, like PHP, Nucleus CMS, and others.
Dailybits Already a long time user of the nucleus cms (2550) with my private weblog about windsurfing, tech and other things (in dutch).