I'm not sure Bungie counts as an acquisition since there obviously was some sort of exit clause. But the Halo IP has to be the best acquisition. Halo pretty much made the XBox was it is. You'd still have Playstation without Naughty Dog. I'm not sure we'd still have XBox without Halo. It's a huge franchise for Microsoft.
Since some have expanded the conversation beyond the big 3 console manufacturers, if we're talking any acquisitions, the acquisition of Blizzard by Activision takes it. But even that doesn't really count as an acquisition. It was a merger.
So we're back to pure developer acquisitions. Based on that, I'm going to agree with most of you and say Naughty Dog.
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