Focusing on achievements after acquisitions, those three companies, and not including incomplete acquisitions like Nintendo did with Rare:
Though Microsoft only owned Bungie from 2000 to 2007, but the games they made during this period, the Halo trilogy, was essential to the Xbox family. All three games were regarded as top tier games upon release, and became system sellers. They were so successful, that the Xbox brand is strongly associated with shooters.
Combat Evolved dominated the early Xbox library, making the Xbox a viable contender for the best contemporary console for multiplayer thanks to its cooperative play and support for up to 16 players. Halo 2 was the game that made online multiplayer a big deal on consoles. Though Xbox Live had been around for two years, Halo 2 is what made it last, and convinced people to transition to the Xbox 360 for their online gaming. Halo 3 helped the 360 dominate the PS3 for a whil in America; the PS3 sold about 55% as much as the 360 in 2007 despite following up the PS2. And besides Kinect Adventures, Halo 3 is the best-selling Xbox exclusive ever.
Nintendo is as sucessful as they are because of the games they made. Playstation is where it is because of support from 3rd parties. Xbox reached its place via an acquired developer.
Love and tolerate.
