[C19fan]

I remember some show that talked about this issue. They envisioned cube shaped ships firing lasers. Since there is no absolute orientation in space a cube would have equal thrust in all dimensions. The major difference with this article is the laser would be the primary weapon and combat closer in.

[Jewbacca]

I would think a sphere would be stronger and deflect more damage.

[gura]

Also if you have to repair a cube in space all you have to carry are flat plates.