What kind of "mansion" do you want? I think you should narrow your geographic choices.

There are very few mansions in some of these locations, and a Novi location couldn't be more different than a Boston Edison location. Except for one small neighborhood near 8 Mile, I don't think I've seen mansions in Novi. Mostly tract homes and McMansions. Same goes for Troy, Farmington Hills, and Commerce [[though there are large homes on lakes in Commerce).

If you're defining mansion as "very large home on large lot" look in Bloomfield Hills/Township especially, and, to a lesser extent, Franklin, Oakland Township, Orchard Lake, Grosse Pointe Shores.

If you want an older, classic mansion, look only in Detroit and the Pointes [[again, mostly Shores).