First which comes to my mind is Mojang

I mean, the one that has by far produced the most profit has got to be Mojang. They just keep selling an already made game with minimal updates and release games with graphics small teams can make, pure genius move by Microsoft.

I think that is debatable.

Sony got Insomniac for 220M or so, a massive studio with 3 - 4 development teams, and as part of SIE they already pumped out Miles Morales (20M+ seller), R&C (5M+ seller), with SpiderMan 2 (30M+ seller potential) & Wolverine (20M+ seller potential) scheduled to be released in the next couple of years. Unlike Minecraft, or any of its spinoffs, the Marvel properties Insomniac is working on can move hardware and drive subscription rate growth. 

Moving hardware doesn't mean much when you have +700 million players of minecraft(more than total Playstation HW sold) and almost 150 million monthy active users. Became a top Japanese video game publisher thanks to Minecraft sales alone, Became the most watched video game on youtube + 1 trillion views.

Having the ability to move hardware, or drive subscription growth, is absolutely crucial in this generation of gaming when the industry is shifting. As popular and profitable as Minecraft is, it won't move the needle for Microsoft in terms of expanding the Xbox brand, Minecraft was already one of the most popular games before Mojang was acquired.

Insomniac obviously, but also Guerilla I think. They have made an amazing engine and whilst the Killzome series was hit and miss, Horizon has been a massive succes so far.

Very hard disagree.

Insomniac was basically a 2nd party studio for Sony anyway, so the acquisition had 0 impact on software or hardware sales. Sony's not gaining a single new customer from Insomniac as those games would've been developed by them anyway or do you seriously think that Insomniac wouldn't have been interested in a Spider-Man sequel after those sales??

The only good result from the acquisition is that Sony can now reap all the profits from their games and not just part of it.

Insomniac has released an exclusive game for Xbox and they tried there luck at multiplats with bulletstorm. Not that those ventures where worth it. Anyway Insomniac was a good buy, because now all games Insomniac produces are Sony exclusive and Sony could expand the size of Insomniac much quicker than they could do themselves, since for Insomniac the pockets of PlayStation are very deep. Also Insomniac could have pulled a Quantic Dream.

Sony buying Insomniac takes the possibility of them being acquired by someone else off the table. What happens if Insomniac was looking to sell but Sony wasn't interested? You think they remain as a second party studio in that scenario?

Also, having them in house means Sony gets a lot more content to supplement their platform. VR games like Stormland, Edge of Nowhere, Feral Rites, The Unspoken were Oculus exclusive and didn't even make their way to PSVR as late ports.