I'm one of those "It depends" types, but in my case it depends not upon my mood, but upon the author's strengths and weaknesses.
I ALWAYS have to have sex (that's why I'm at this site). Some writers are lousy at character development and some just don't bother, but still write great sex scenes. I think of them as 'comp tapes', enjoy them, then move on. Usually if I've sat down to read and review ten to fifteen stories in a night, a no-plot is the ideal story for me to finish with (if you know what I mean). I always read (and review) without my pants on.
When a story is also engaging on a plot/character level, this is a welcome plus, but it requires a LOT more skill from the author and so I think of that as a happy bonus, rather than a requirement.
(Special to Finding_Fantasy: I PMed your hubbins a few days ago and, among other things, bemoaned your absence from the Forum. As I have progressed in working my way through the past three months' threads I see that I was, happily, mistaken. It's good to see you around. Your level-headed and thoughtful contributions are valuable.)