My favorite RPG publisher? West End Games.
They are not publishing any more, but West End Games had a very good sense of publishing game material that seemed to match both the source material and how gamers would likely play it. Some games have a pretty strong disconnect between the creator's original intent and how people ended up playing the game (Cyberpunk 2012, for example), but West End seemed to capture the slightly tongue-in-cheek humor and "Hollywood action" that most gamers seem to enjoy when they sit down at a table.
West End Games published Paranoia, Ghostbusters, and the first Star Wars RPG as examples of their high points as well as lesser-known works such as TORG and Shatterzone. For a time they acquired licenses to large numbers of sci-fi and fantasy TV or movies such as Tank Girl, Species, Indiana Jones, Men in Black, and the Hercules and Xena TV franchise. They also did one RPG for DC Comics, which like many licensed superhero RPG featured nice write-ups for the comic book publisher's characters but lousy rules for PC creation.
Two pretty well known names that came out of the WEG stable are Greg Costikyan and Bill Slavicek, the latter of which went onto develop the third edition of Dungeons and Dragons (among many other games).