I googled it on a whim, after watching a Teenage Mutant Ninja Turtles episode:
Unicron vs. Death Star
Unicron. Definitely Unicron.
I can’t believe I have an opinion on this.
See, I just can’t agree; I found the argument in favor of the Death Star pretty convincing. Let’s start with the indisputable premise that the Death Star has very significant advantages with respect to both speed and range. (Moreover, it could also have a stealth advantage, too; Unicron may well begin the fight overconfident, taking it to be a moon rather than a space station.) The fight will be on grounds of the Death Star’s choosing, and the Death Star will get the first shot, with its giant superlaser. Moreover, that first shot will almost certainly hit; if the superlaser can hit moving spaceships, it can hit Unicron.
So now there’s just one question. Will the superlaser destroy Unicron, or can he really only be harmed by the Autobot Matrix of Leadership? The article is pretty convincing on this point:
Now I know what you’re saying, “Only the Matrix can defeat Unicron,” right? Wrong. Did any of the Transformers have a moon-sized space station with a giant laser on it? No, they didn’t. Quite simply, the Death Star would rip Unicron a new one, and then it would rip him a second new one if he were lucky enough to survive the first blast.
Clearly, it goes to the Death Star.
I mean, it’s clearly the Death Star.