OK, thanks for your honest opinion.
I really like the skyline of Frankfurt and its skyscrapers.
The city has a good mix of architecture and different facades.
And of course it's in my home country.
My favourites are: Commerzbank, Messeturm, Westend Tower, Main Tower, ECB, Grand Tower and Omniturm.
I got the list from Wikipedia:
List of tallest buildings in the United States
Philadelphia ranks 12th on US list and 17th on my list.
Toronto is of course not included.