My old Altec Lansing 2.1 system from ~2004 draws 7W (yep, seven watts) according to my BluePlanet meter even when it's "off". I only have it plugged in when I don't feel like using my headphones.
<OT>
It's still not as bad as my Rogers cable box which draws over 15W unless it's unplugged
I put that on an old Christmas tree timer so it's only being a parasite for half the day.