If I find myself in a crisis, I will happily work on, but that happens quite rarely, other than that, give or take the odd ten or fifteen minutes, I stick to my hours, and I never, ever take work home with me. This means I have a significant amount of paperwork on my to do eventually list. I receive no sympathy at all as half the team not only take work home every day, but start work at 7.30 as well, so the rest of us look incompetent. We really don't do ourselves any favours.
Of course, if I spent less time on here I could get more done, but I class this as reflective practice!