I go to bed at midnight Sunday through Thursday nights and then up at 7:40am Monday through Friday, so just shy of the "average" 8 hours.
However, whether or not I sleep well is completely dependant on things going on in my life/mind. Sometimes I can hit the pillow and be asleep within fifteen to twenty minutes, other nights I will lie there for hours on end, sometimes not sleeping until around 4am or even later. I've never been a good sleeper.
Lack of sleep however has never seemed to really bother me, I typically fall back into routine the following day, just not feeling quite so fresh.
The only thing that has changed recently is that I no longer sleep until 11am on the weekends. I now get up at 8am or 9am. That's not because I'm bothered about missing out on the day (even though I am), I just simply cannot do it anymore.
Oh, and if I've had a few beers or more, I don't sleep properly. I lie there utterly wired.