Located at the Lotte Department Store in Busan—the second largest city in South Korea—this mesmerizing fountain actually plummets five stories from the ceiling. And as the water drops tumble towards a small pool on the ground, they create complex designs and even spell out words like "Busan" and "Lotte." The ten minute show, which runs at the top of every hour, could give the waterworks at the Bellagio in Las Vegas a run for its money. [Busan For 91 Days via Neatorama]
I'm not so sure about the accuracy of this article. The Compuware Building in Detroit, MI actually has the tallest fountain that I'm aware of at over 14 stories tall. This is taken from wikipedia:
"The building's water feature was designed by WET Design, the same people who designed the fountains at Bellagio and the Winter Olympic cauldron. It features fifteen glass "kites" and, at more than 14 stories tall, represents the largest indoor, hanging water feature in the world."