Because of the great records in Canada, I sometimes wish I had Canadian ancestors. If your Canadian ancestor lived at the time of World War I, the Canadian Great War Project will definitely be of interest.
It claims to contain the largest fully searchable database of Canadians serving in the First World War, or other nationalities who served in the Canadian Expeditionary Force (CEF). The site differs from others like the Libraries and Archive Canada sites, or the Canadian Virtual War Memorial by making all information, including birthplace or next of kin, available as part of the search criteria, making it very useful for genealogical research. There are currently over 70,000 entries, with more being added daily. The site includes many other features, including transcribed/searchable war diaries, book reviews, transcribed letters, images and statistics on Canada in the Great War.
Visit the Canadian Great War Project at http://www.canadiangreatwarproject.com/