Depends on which approach is in use. If it's from the south over Tokyo Bay to 34L/R, the left side so that you can see Mt. Fuji if it's not too cloudy. If the winds shift and it's the approach from the north to 16L/R, then the right side would see Fuji, though both sides would allow you to admire Tokyo as you come in. If it's from the east to 04/05, then you don't get to see Fuji, but the right side would allow you to see some of the Tokyo skyline.

It's really luck of the draw, but I would say that the approach from the south is the one most often in use, so grab a left seat if available.