The thing about 9/11 that got me was how the towers fell. The manner in which they collapsed was unlike anything I've ever seen. There is simply nothing to compare it to. How does a 100 story high rise shatter like that so evenly from the top down? Not even controlled demolition can do that.
From what I've heard from the experts, apparently a controlled demolition can indeed do that. That's what it looks like to me from the videos I've seen of controlled demolitions.