I just wanted to say that I love these two games and neither are unplayable, but they definitely could both be mentioned in the same post. =)Among actually supported games it's RIFTs . Completely unreadable combat rules scattered in character creation, total nonsense class options ranging from hobo to Fin Fang Foom. Entire sourcebooks, NPCs, based off random commissioned concept art. 99% of weapons and armor are completely obsoleted by a class that gifts you a god suit of armor. Random snake oil sales pitches from Palladiums owner who randomly talks at the reader and uses weird punctuation. Books laid out like they used glue and scissors.
Among obscure games it's gotta be Synnibar.
No one mentioned Senzar yet, so I'll bring it up. The rules make sense I guess, but the only published book is basically only rules for making characters and has no tools for the GM.