Normally, about 8 or 9 hours, give or take. Sometimes 10, if left to my own devices.
Depressed, at least 12-14, sometimes longer. Mostly what you'll catch me doing is napping at every opportunity even when I've slept for 11-12 hours but those little catnaps add up.
Mania, uhh... we don't need no stinkin' sleep! Seriously though, this one varies. On average, 3 or 4 hours. Sometimes less, sometimes more, very rarely more than 6 though. And I wake up feeling completely refreshed, whereas when I'm not manic/hypomanic, if I get less than 7 hours I'm groggy and exhausted the rest of the day.