Oh lord. I always set out to write just one-shots, and then I can't fit it all into just one chapter, or the stopping point is just too good to leave, or I have a little addendum to the story that shows up in a second chapter, just for shock-value (I did that recently with my Death Note fic, "Kitty" in which the Master's name is revealed in the second chapter.)
I prefer to read long, in-depth, detailed things, but I love reading short little witty-one offs, as well.
One day, I hope to write a rockin' novel length fic (with more than twenty pages per chapter, and more than thirty chapters total.) but I have issues with finishing things. Either I just get fed up with the story, or run out of inspiration, or run out of motivation, or I get distracted by a newer and shinier story that demands to be written...
I have writers-ADD.