Real 3-D Goban
In this category fall gobans which actually have 'liberties' in three dimensions. In order to have a regular goban, crystal lattices as encountered in chemical molecules have served as inspiration.
Stacked cubes provide inside points with many liberties (up to eight), and it is difficult to attack groups. Similarly with stacked pyramids (up to 12 - even worse).
So far, the most 'playable' alternative found has been the 'diamond' lattice for carbon.
Henry SEGERMAN has gone quite far here, and proposes a working 3D goban, and also has a computer program which allows you to view and play on a 3D goban. Check out his site here.
Lukas Biewald created a 3D lattice based game, but the associated webpage no longer exists.
There is a marble stacking Go variant by Cameron Browne called Margo. It can be played on
Richard's PBeM Server. Cameron has written is a free
ebook on how to play.
Brett Nelson created a 3D go program, more information here.