We use whichever site has the best deal.
Usually we use
www.Escapes.ca or
www.Expedia.ca
or
www.Orbitz.com
We have also used
www.Redtag.ca and
www.tripcentral.ca
Great results from all of those.
Or we book directly with the airline and hotel ourselves, or like Lindalou, condos directly from the owner with sites like
www.vrbo.com .