Mine is "Will you turn that down?" This can be applied to: Telly, stereo, hob, heating, fire, dimmer switch, phone volume, and sometimes even his voice! I think he's a bit deaf - he shouts over whatever appliance he's just turned up, and has everything MUCH louder than I have it, and I'm always a bit too hot whereas he's freezing 24/7!
(And my other favorite is "not in a minute, NOW!"
)