Lots of Coach and LV - I agree with the OP that access to boutiques has a lot to do with it, there is a big LV and a big Coach store near me.
I was in a mall the other day that has a Coach and it felt like 80% of the women I saw had Coach.
I have a Kate Spade that I bought at Winners (Canadian discount designer outlet) and I've never seen anyone else with KS (Winners gets a small amount of the mid-range bags like KS and Coach, most of what they have is Guess, Tommy Hilfiger, Kathy Van Zeeland and such).