UK Directory: Huge directory that bills itself as the largest UK directory of reviewed sites. And it is - the first couple of results are paid listings - followed by ites that have been reviewed for inclusion.
UK index: UK index is a directory of affiliate links.
UK Plus: Uk Plus has been around for a long time. All of the links appear to be paid rather than reviewed.
uk websites directory: Based on the uk250 web directory. Basically uk250 results in a different format.
UK Wizz Directory: UK Wizz is an exciting new UK search engine. This is it's directory. Not as many listings as other directories but growing all of them time.
uklinks.org: growing directory of uk websites that are hand-reviewed for inclusion.
Weblistings.co.uk: small but growing directory of uk sites. Sites are reviewed before being included.
Yahoo UK & Ireland directory: huge and rightly famous directory of hand-reviewed websites.