Coming in at #7 for top publisher is Microsoft.
Microsoft have been publishing games for a long time – the first Microsoft published game I played was in fact Microsoft Decathlon back in 1982 – although it’s probably debatable whether I can truly include this game considering Microsoft did not have a dedicated game publishing arm at that stage (as far as I know).
The biggest franchises published by Microsoft would have to be Age of Empires and Fable. Back in 1997, I tried out this new Real-Time Strategy (RTS) game that claimed to be different than the sci-fi and fantasy offerings of Westwood Studios and Blizzard. This game, by Ensemble Studios, was set in ancient human times and involved guiding your humble tribe from the Stone Age to the Iron Age. It was an addictive game and its legacy can be seen in such recent memes as "Wololo". The game also had an intuitive level editor to boot. Its sequel, the medieval Age of Empires 2 (1999), added even more civilizations to play with and was critically acclaimed.
While often over-hyped by Lionhead Studios’ Peter Molyneux, Fable, released in 2004 on PC, was still a fun RPG. Like Knights of the Old Republic, the game allowed you to perform good or evil actions and this would change your alignment (and appearance) as a result. Sadly the PC never got a version of Fable II but we did get the opportunity to play Fable III (2010) which was set in an Industrial Era Albion. Fable III was interesting in that it played with the idea that being a hero often meant choosing the lesser of two evils.
QBASIC; Starlancer (2000), a space sim by Chris Roberts which is similar to Wing Commander; Freelancer (2003), a sensational space trading sim by Chris Roberts, similar to Privateer; Rise of Nations (2004), an RTS that is a winning combination of Civilization and Age of Empires, and Jade Empire (2005), a Bioware RPG with a Far Eastern setting.
Will I continue to buy Microsoft games in the future? It really depends on a couple of things. Firstly, Lionhead Studios appears to be taking the approach that it will only release games on console which means Peter Molyneux is unlikely to get any money from me in the future, no matter how good his games are. Secondly Microsoft doesn’t seem to be doing much with some of its better IP like Age of Empires or Freelancer. The most recent Age of Empires game, Age of Empires Online, didn’t rate well and Freelancer is unlikely to be touched ever again considering Chris Roberts has seemingly left the game development business (his brother, Erin, still works in the industry though...).