Q-BA-MAZE was invented by architectural designer Andrew Comfort, with inspiration from architectural principals and his grandfather's wooden marble maze. For me the Q-BA-MAZE toy combines the Japanese time burning game Pachinko with Lego building blocks.

With Q-BA-MAZE you can build visually interesting buildings and then have a steel ball race through them from top to bottom.
The Q-BA-MAZE 50 piece set sells for $45.95 on Amazon.com. See also the Q-BA-MAZE site for building plans.

If you are not into building stuff, you can get an original Pachinko machine from Japan on Hammacher.com for only $329.95.
These Pachinko machines are refurbished originals coming directly from the world famous Ginza in Tokyo. As you turn the knob, steel balls are propelled into a maze of spinning wheels, bumper-action pins, and bonus pockets. Lights flash, bells ring and music plays when balls trigger the jackpot, earning extra playing balls. Solidly constructed of wood and steel, each comes with 400 balls.
More details on Hammacher.com.