Pre-existing universe or own world?

Because I like to play games that are set in a pre-existing universe, like Star Wars, LOTR, Harry Potter or Fallout etc. , I just want to know what the opinions of you fellow Fabletoppers are to this topic. Do you rather like to play in a world completely created by the GM, a generic medfan/scifi/whatever game or in a movie/book/game universe? Maybe a mix from all of them? Just share your thoughts.

Personally i like it when the GM puts effort into making a detailed world that is also very open to modifications. I much dislike worlds that are blank slates where nothing in a location exists until the party has to go there, but i also absolutely hate worlds which are so uptight in their locations, characters and lore that your character is relegated to forever being a background character in some other grand plot that is unveiling around them.

As for pre-existing universes, i think that with some exceptions few people ever do campaigns in pre-existing ones and prefer to go the custom route since it allows for more, well, customization. If you go with an existing universe, you have to play by their rules. In a custom universe, you make your own rules.

Yeah, I like to play in custom universes too, donīt get me wrong. But I also like to play out a new story inside an existing one. Like how Luke and Han could fly with the Falcon so easily (because someone sabotaged most of the Tie Fighters in the RP) , or just side characters that do not interfere with the original story but rather add their own to it. The people from Saving Throw (a channel I appreciate) did that with Harry Potter in some way. And they added the Chickenbear Day as the wizardīs carnival, what I now take as my personal canon.