Personally, not much.
In winter, when its frickin’ freezin’ I wear LaSenza PJ’s with the pants and little strapy top.
Summer - nada.
So - what do YOU all wear?
briefs
24/7/365
Can’t sleep nude. Too hot for jammies down here.
B-day suit. 
People WEAR things to bed?!?
Plato? Aristotle? Socrates? Morons!
~I know it wasn’t right, but it felt so good… -Better Than Ezra
Summer: nightgown or big t-shirt
Winter: sweatpants and long-sleeve t-shirt. Occasionally a nightgown or some pajamas
summer:
snazzy Hello Kitty jammies. (choice of 4 to mix and match!)
or
cotton gown
winter: polartek jammies with feets on em! personalized even!
summer: nothing.
winter: either an old T-shirt or nothing if I’ve got someone to keep me warm 
Home
Hot: Boxers and a t-shirt/singlet
Cold: Pyjama bottoms and a t-shirt/singlet
SO’s house
Wear something to sleep in? You mean, like, clothes? Wear clothes to bed?
What a … strange idea.
Nothing, simply because I hate to be hot when I sleep. In the dead of winter I’ve got the window open, the fan blowing on me, and no covers on.
Hot: nada
Cold: what ever comes to mind. Last night, socks.
I just wanted to get under Booker57 while he’s wearing his nothing !
I usually sleep either nude (hubby’s favorite) or in a really big night shirt (flannel ones if it’s really cold. ) and that’s it.
With spouse - nothing.
When spouse is on travel (like this week) - big T-shirt.
Either a t-shirt & panties, just panties, or nothing. It really depends on my mood and how warm I am. Usually it’s just panties.
Briefs - summer or winter.
Nada, all year round.
I’m with you there - window open, everyhting. I have even woken up with snow drifts on my bed!!
ditto
Depends on the weather. I have lots of cute pajamas for when it’s cold. On warm nights, usually just underpants and a t-shirt or a tank top.
Boxers.
The only time I can ever sleep in the alltogether is when I have company. It just feels odd otherwise.