•  1901 British Census 
  Unfortunately as much a government revenue-raising exercise as a service to genealogists. Be sure you know exactly what you are looking for before you spend any money!
•  Ancestry.com — Free Births Marriages & Deaths index
  
•  Census Records 
  This is also something of a rip-off, though at least you can get an annual subscription.
•  Commonwealth War Graves Commission  
•  Cyndi's List — useful UK sites  
  One of the most comprehensive guides to genealogical websites
•  FamilySearch Internet Genealogy Service  
  Now includes the 1881 British Census on-line and free.
•  GenForum — surname forums  
  Find other people looking for the same surnames as you.
•  GEN UKI Genealogy UK & Ireland  
•  General Register Office  
  Order official copies of UK birth, marriage and death certificates.
•  LDS Church Family History Resources  
  Excellent free search resources
•  Scotland's People  
  Official Scottish records. Another money-raising exercise, be sure you know what you want before you spend any money. Also beware that the quality of images returned is poor as they have been saved as 1 bit images (i.e. each pixel is either black or white, there is no greyscale) this can make reading difficult.

I am getting rather fed up with the attitude of some government and government-backed genealogy-related websites. Somebody in government has clearly decided that the interest in Genealogy is a nice little earner. Many of these sites have petty pricing policies where you are forced to pay a fixed amount, and then have to make use of that payment within some pathetically short timescale or you just loose your money. The Scotland's People site even forces you to pay to see search results, even though those results may be of no consequence whatsover.
A sea change is needed so that people only have to pay for records they know to be relevant.
Apple's iTunes service is an excellent model of how this should work. Searches are free, previews are free, you only pay for the actual item, and you only pay a small amount per item.
 
Other Information

UK residents can obtain the
1881 British Census on CD-ROM, price £29.75
from:
 
The Church of Jesus Christ of Latter Day Saints
Distribution Centre
399 Garretts Green Lane
Birmingham
B33 0UH
 
For elsewhere order from:
  http://www.ldscatalog.com

•  Allman  
•  Beckett  
•  Bradshaw  
•  Coleman  
•  Dicker  
•  Fielding  
•  Greenhalgh  
•  Harvey  
•  Jarrett  
•  Johnstone  
•  Lupton  
•  Mayoh  
•  Pover  
•  Roberts  
•  Starnes  
•  Thelwell  
•  Ward  

•  Allman 
• The Harvey Genealogist 

•  alt.family-names  
•  soc.genealogy  
•  soc.genealogy.britain  
•  wales.genealogy.general