Coming in at #6 for top publisher is Microprose.
Like Virgin Interactive, Microprose is sadly another defunct studio. It was originally formed in 1982 by legendary game designer, Sid Meier, and Bill Stealey, a retired USAF Lieutenant Colonel. The company slowly died off during the late 90s with the 2002 game, Geoff Crammond’s Grand Prix 4, being the last to have a Microprose logo on the box. The first Microprose game I can ever remember playing was Covert Action (1990), an old EGA game where you played a secret agent, flying around the world apprehending dangerous terrorists.
Master of Orion (1993) was another sensational game which was basically Civilization in space, so it made sense for Microprose to publish this franchise! The best features of Master of Orion though were that each race had different benefits and best of all, you got to kit your own ships with the technology you researched! Master of Orion II (1996) would continue with this formula and just like Civilization, I became a Master of Orion fan.
Other games that I've bought from Microprose include Sid Meier’s Colonization (1994), a strategy game that simulates the founding of the United States; Transport Tycoon (1994), the best transport company simulator I’ve ever played; Worms 2 (1997), the best version of Team 17’s take of the artillery game genre, and Mechwarrior 3 (1999), a highly realistic battlemech simulator (if you can call piloting battlemechs, realistic)!
As Microprose is defunct, no-one will be buying games from this publisher any time soon – unless they decide to resurrect the brand name of course! 2K Games is the natural successor though as it owns Firaxis.