2 to 3 hours most of the time but I am trying to shift my schedule around now because I'm getting a little older and the lack of sleep is starting to catch up to me.
I have totaly bad sleeping habits, during week i sleep from 3-7 and try to get some more from sleep by 10 during weekends.
I sleep 6-8 hours, usually. There are some days during which I only sleep 4 and sometimes more than 10 on other days.