Family Search - Excellent Search Engine (Includes International Genealogical Index data).
War Graves - Good search Engine (Includes some parental information).
GOONS - Guild of One Name Studies.
The Guardian - The 50 Best Web Sites.
Free BMD - Births Marriages and Deaths - Look up and searches.
TNA - The National Archives.
Directgov - Births, marriages, deaths, adoptions and civil partnerships.
ONS - Office for National Statistics.
Genuki - Genealogy in the United Kingdom and Ireland.
Rootsweb - United States based and has lots of information and links.
Ancestry web sites:
Ancestry UK - Featured sites about UK Family History.
Ancestry International - The World's Largest On-LIne International Collection of Immigration Records.