A few words before we begin:
For the purposes of this ranking, a "house hunting program" has been defined as one in which the main purpose of the series is for prospective homebuyers to tour multiple properties and decide which among them to live in. This leaves out certain programs, like Property Brothers and Love It or List It, which do feature house hunting but are arguably more focused on home renovation.
This ranking has attempted to take into account every house hunting program that HGTV has ever aired, although that is by no means a guarantee that I haven't missed a show or two. Sorry.