Ancestry.com - United Kingdom - Census and Voters Lists

These include:
• 1841, 1851, 1861, 1871, 1881, 1891, 1901 and 1911 census for England, Scotland (not 1911), Wales, Channel Islands and the Isle of Man. The records are fully indexed with a free surname search. A variety of subscription options offer access to the digitised copies of the original records. Note that only transcriptions are available for Scotland not digitised copies of the original record.
• London, England, Electoral Registers, 1832-1965
• Midlands, England, Electoral Registers, 1832-1955 
• UK, Poll Books and Electoral Registers, 1538-1893
• Dorset, England, Electoral Registers, 1839-1922
• Suffolk Returns From the Census of Religious Worship of 1851 
• Lincolnshire 1818 Poll Book
• U.K. Census Free Sample
• County Antrim, Ireland 1851 Census 
• Ireland, 1841/1851 Census Abstracts (Northern Ireland)
• Ireland 1766 Religious Census
• Ireland Householder's Index, County Antrim 
• Fife, Scotland, Voters Lists, 1832-1894
• Perth, Scotland, Survey of Inhabitants, 1766
TIP: Ancestry is available for free, onsite, at some state, public and family history libraries. Check what might be available onsite at a library near you.