I am a sucker for a good story.
While I certainly feel that I can appreciate good writing when I encounter it, it is in no way a prerequisite for my enjoyment of a particular book/movie/TV show. For example, I kept thinking about the plot of Gone for Good by Harlan Coben even though I think the actual text may have been written by a monkey. I totally did not see that ending coming. I also couldn't stop watching the third season of Veronica Mars even though the show had jumped the shark so high and far that I couldn't believe it hadn't been cancelled.
Mercifully, I have lately encounter several instances of that rare, delicious combination of good writing and a good story.
And what happens when you have neither? Ugh. I'd rather not talk about it.