Personally for me you have to strike that all important life/work balance.
I work in a sales job and a lot of my colleagues regularly stay late to hit targets etc. I fail to see why they need to do this as I am very rarely at work past the officialy 6pm clock off time, more commonly sneaking off for an early finish too and yet have been top earner for the last two years in a row.
Work smart, manage the diary effectively as in my opinion you don't often get the thanks that you would want.