People are testy because it has been explained about a million times that the point of the thread is to compare cities based on their
metro area populations, not
city proper populations, yet people continue to post based on city proper.
Anyway, Colorado Springs has been mentioned a couple of times. It shouldn't be. First of all because it just barely doesn't qualify (metro area population: 617,714 as of 2008), but also because it has a very weak skyline for a region that large. The tallest building is less than 250 feet.
source