Palladium Books' is a company founded and mostly run solo by Kevin Siembieda. It has produced around 15 separate settings all using a single semi-standardized game system. It is about on the same level of complexity as D&D 3.5e, but may be harder to learn from the book because of layout (depending on the which book you use, some are weirder then others, opinions fa/tg/uys?).
Their earliest successes were The Palladium Fantasy RPG and Teenage Mutant Ninja Turtles & Other Strangeness, followed by the official Robotech role-playing game. Their most popular product to date is the Rifts RPG and setting.
- After the Bomb (post apocalyptic furries)
- Beyond the Supernatural (CoC esque)
- Chaos Earth (A RIFTS prequel as the world descends into grimdark)
- Dead Reign (BRAAIIIINSSS, an example in how to screw over the original author and pay him almost nothing for his work)
- Heroes Unlimited (Supa Heroes)
- Palladium Fantasy RPG (the Mechanoids may have been published first, but this was Siembieda's original baby.
- Nightbane (Totally not Nightbreed, we swear; google high octane nightmare fuel)
- Ninjas and Superspies (... that was easy!)
- RIFTS (MOAR MEGADAMAGE)
- Robotech (yes, the anime ones)
- Robotech RPG Tactics (a miniatures game where you accrue $1.4 million dollars in kickstarter money and then flush it all, one bill at a time, down the drain over the next four years).
- Mechanoids (Totally Not The Daleks, we swear)
- Recon ('Nam)
- Splicers (Guyvers vs Skynet!)
- Systems Failure (Y2K is REEEEEEAAAALLL.. and caused by inter-dimensional insects)
As well as the aforementioned Ninja Turtles, and a few non-setting specific sourcebooks such as the weapon compendiums (made to be at least useful, if not easily adaptable to any system), and the quarterly released Rifter (a hodgepodge of material that never made it to the source books along with fan-submitted homebrews Kevin made semi-canon).