The Most Deprived Area in England is…
the Lower Super Output Area E01021988 located near to Tendring in the East of England. This output area was ranked the third most deprived area in 2007. The most deprived area in 2007 was located in Liverpool (E01006755), which in the 2010 classification is now ranked sixth. I would claim this is due to my recent move to the city, however unfortunately the data pre-date my arrival. Deprivation in seaside locations is explored in this DCLG report from 2007.
The Index of Multiple Deprivation 2010 is available to download here.