Ancestry has a large number of record collections for births, deaths and marriages in the United Kingdom and Ireland. Some of the main collections I have used include:
England, Select Births and Christenings, 1538-1975
England & Wales, Marriage Index, 1916-2005
England & Wales, FreeBMD Marriage Index, 1837-1915
England & Wales, Birth Index, 1916-2005
England & Wales, FreeBMD Birth Index, 1837-1915
England & Wales, Death Index, 1916-2007
England, Select Marriages, 1538–1973
England & Wales, FreeBMD Death Index, 1837-1915
London, England, Marriages and Banns, 1754-1921
London, England, Births and Baptisms, 1813-1906
England, Select Deaths and Burials, 1538-1991
England & Wales Christening Records, 1530-1906
London, England, Baptisms, Marriages and Burials, 1538-1812
England & Wales, Non-Conformist and Non-Parochial Registers, 1567-1970
West Yorkshire, England, Marriages and Banns, 1813-1935
England & Wales Marriages, 1538-1940
West Yorkshire, England, Baptisms, Marriages and Burials, 1512-1812
London, England, Deaths and Burials, 1813-1980
West Yorkshire, England, Births and Baptisms, 1813-1910
Ireland, Select Births and Baptisms, 1620-1911
A complete list is available at http://search.ancestry.com.au/search/CardCatalog.aspx#ccat=hc=25&dbSort=1&filter=0*34%7C1*3257&
