I don't know. Most "worst" or "bad" Game i don't remember. There are only very Few examples where i really hated an Game - like Final Fantasy 3 (and thats one of the more popular ones) or Dead Linger/Stomping Land(no RPGs). Or Ride to Hell, if you played that once, you will see that complain about Games like Skyrim are laughable.
Most Time, if i read such Questions, and see some Answer, i get more the feeling of most People want rant about Popular Games, for the sake of ranting. I mean Skyrim, Mass Effect 3, and so on? I mean i won't talk down that some might dissapointed about this Games and i get even the Reason(even though i mostly don't share that) - but to call out this Games, did you Guys actually really play "bad" Games, which deserved to be called bad? I mean like i said, i hate Final Fantasy 3 - but even thought i dislike it, i wouldn't call it as "worst" - because i still can see the Quality behind it. And even if we argue about Skyrim(as example) how bad it might be compared to previous ones, or Divinity, or Witcher 3 - and even if it would be "true", Skyrim is still far away from an bad Game and even Mediocre would be way to much. It still have an High Quality Standart, only goes an different Route.
But im done with my Argument =) I don't want to talk down your opinions, i only want to share my own Viewpoint if i read about such things =)