One Ugly Black Stick
This, in my opinon, is the ugliest blight upon the Manhattan skyline, this stunning photo of mine notwithstanding. The Trump World Tower was finished shortly before September 11, 2001 and I remember hearing that mentions of its immense height were immediately stricken from press materials, in the hopes of making the building less of a target for terrorists. It was the tallest residential building in the world, briefly, and the only really cool thing about it is the 600-ton mass damper that slides back and forth on the roof, to quell the swaying that such tall slender building must withstand. This is one ugly black stick, folks. Blech. (Here's a cool site to look at some of the tallest buildings in Manhattan, existing and proposed.)
EDIT: Perhaps the picture below better illustrates how ugly this building is. It looks like a smokestack with windows. Click on it for a huge version.