Okay, I'm going to try for some serious answers (ie: not something ridiculous like Level-5, Epic Games, Square Enix, Capcom, Sega, Rockstar, etc).
Nintendo buys Next Level Games. They've had multiple close successful partnerships, the last of which was even a hugely acclaimed classic IP revival (Punch-Out!). Not many companies can do that, NLG doesn't come with much overhead/baggage and it'd help strengthen Nintendo's flagging western R&D. Seems like a good match from every angle imo.
Sony buys Q? Entertainment. Y'know, when Miziguchi originally stormed out of Sega rather than work under Sonic Team (and took half of UGA with him) I always figured he'd have gone to SCE. It really just seems like the sort of place that'd fully support his design sensibilities and he could make a team like UGA flourish. There's just a similar feeling there, games like REZ or Space Channel 5 were totally games I could see coming out of SCE Japan Studio (Kaz even complimented REZ publicly, and that was back when Sega was the competition). Plus if Q? went to SCE, they could concentrate fully on doing trippy shooter/puzzle/rhythm hybrids and not have to waste time on Bandai fighters or Disney adaptation to stay afloat.
Microsoft buys Bluside. This one might be more controversial, as Bluside has a pretty strong PC presence and Micrsoft seems eager to kill PC gaming dead asap, but I still think it'd be a good match. Microsoft clearly loves Kingdom Under Fire, they really do need more of an eastern R&D presence, and Bluside loves money. If Microsoft can drive Korea as real center for consoles with better home grown content, then all the better too.
