"10 and 2" is what many people traditionally think, though I've found that holding the wheel above the "racecar driver" position leads to jerky, unsure turns (many of my friends hold the wheel like this and I refuse to let them drive because it's terrifying), and at the driver's ed school I went to we were actually taught to hold at 9 and 3.

Ok, oppo: Where do you hold your steering wheel?