Ask Jeeves: the webs favourite butler. Ask him a question and he'll serve you some results. The results at the top of the page are paid links rather than search engine results.
Google UK: the current king of the search engine scene, Google uk serves a uk filtered subset of its massive index.
Lycos UK: uk version of the Lycos index. Used to be a major search engine, but less important these days.
Mirago: uk specific search engine, excellent coverage.
MSN UK: another big player in the search engine game and another huge database of webpages from the UK. MSN also searches Encarta to provide even more answers.
UK Wizz: uk wizz is an exciting new independent search engine covering the UK only. Specialising in serving uk specific results. Constantly growing.
woWWWser: wowwwser is another of the new uk specific search engines. It specialises in serving its own results, is banner free and independent. Growing daily.
Yahoo UK and Ireland: The granddaddy of all search engines. Search through Yahoo's uk and ireland index.