<< shut the hell up. star trek is fake you know. and the death star came before the stupid borg cubical. >>
Yes...star wars is real and star trek is fake. LOL.
Anyway, back to the original question, anyone with any sense knows the Cube would slaughter the Death Star quickly. The only two things the Star has going for it are the big gun and it's limited weakness (although considering Borg technology, it could probably kill it with it's weapons despite the weakness). The Cube, which is extremely manueverable, could either dodge the gun, or when it sees it charging up, move away from it, or perhaps fire a shot at the gun and cause it to either backfire or not fire at all. As for the weakness, they could easily scan the ship in moments and the collective mind working together could easily find that weakness, along with probably many others, and in seconds the Death Star would be a pile of raw materials floating in space, waiting to be assimilated by the Borg.
Case closed.