Tokyo high-rise

This diagram at the SkyscraperPage gives you a great overview of Tokyo's high-rise buildings (incl. Tokyo Tower, pictured on the left).

On number one, the not yet completed, 610m Sumida or Shin Tokyo Tower. If you think Roppongi Hills is bad, you better NOT check out the Sumida Tower website's video section - expect to hear loads of crappy marketing slogans à la "Tokyo's new landmark" and the like.