I have Shapley's list, complete with reigning conductors.
Step right up, send in your 2cents worth. Have an opinion (its free).
Remember, these orchestras record, so many of us have heard more than 10.
I'll post lists etc end of next week, and open the rankings up for discussion and modification, prior to compiling the b.com "official" list of Top Orchestras in North Ameria (note = this includes Canada).
Altoid - curiously strong.