Writer's Fallout Shelter

Well history proves that a fantastic story can save a book. There are many mediocre writers who got famous because their story and characters were unforgettable. I don't believe that gives us permission to write badly. For my own sense of pride I'd like to know that every time something of mine is published it was written to my best ability at the time.

Two examples of mediocre writing saved by story/character (BTW I find it's more often character rather than story that carries it.):

J K Rowling = Harry Potter series. Particularly her first book. You can watch her progress as a writer if you read the series. She grows along with the characters of her books. But ultimately it's the story and character that makes this series unforgettable, the writing improves.

J. R. R. Tolkien = The Lord of the Rings Trilogy. Tolkien was definitely a historian first and a writer second. His books were dense literature and can be challenging to sink richly into. His world, characters, and story however comes to the rescue to keep readers enthralled.

Does anyone else have examples where "story trumps all"?

What about examples where it doesn't? Where the story/characters are weak but the excellence of voice and the cadence of language make the peice? Are any of those possible?

Have fun and keep writing,
Yours truly,
Rebecca Laffar-Smith