Until 11 November, Ancestry is providing free unlimited searches and views of all their global wartime records.
That includes the following, with over 100,000 records.
U.K., World War II Army Casualty Lists, 1939‑1945
U.K. and Allied Countries, World War II Air Combat Reports, 1939‑1945
Canada, Nominal Rolls and Paylists for the Volunteer Militia, 1857-1922
Canada, British Army and Canadian Militia Muster Rolls and Pay Lists, 1795-1850
and many more.