Rarely naked. Undies or some form of jammies, depending on the weather.
Pajamas in the winter, briefs and t-shirt in summer.
My butt cheeks get cold if I sleep in the nude.
I get chilly easily. If there’s no other source of heat, I need to be covered with more than blankets.
As most: Nude except when it would be improper. Even nude when it’s cold–I just use extra blankies. 
I’ll sometimes try to nap with clothes on, but even that’s difficult. Absent persons who might be miffed by my nekkidness, the clothes only remain on if I’m incredibly tired (e.g., I’ve just come off of a two-day Greyhound trip with almost no sleep), extremely drunk, or lazy (see naps, supra).
I would sleep totally naked if I could. Alas, my SO would prefer it. (Whose wouldn’t?)
Unfortunately I often dream lucidly, and thus, “awaken” (not really) in the altogether. This isn’t good for my lucid dreaming state, realizing I’m naked.
Lately I’ve been able to transmogrify myself some clothes if it still happens but thankfully it’s rarer since I started wearing the t-shirt/undie ensemble.
Also, in times when SO is gone, I don’t want to be totally nude when a tree falls on the house or something. Seriously. I think about these things.
If I lived somewhere where it didn’t snow in April I’d probably be a full time nudist. As it is, I sleep nude and have since I was 16.
But it doesn’t do a thing to help my sleep disorder.
When I’m sleeping alone, I usually wear panties. Unless it’s really chilly, then a T-shirt is added. I have some PJs for traveling, but usually slip the bottoms off once under the covers.
When I’m with my SO I prefer to be nekkid. 
Well sleepwise it doesn’t matter, but I prefer to go au natural. Sometimes I feel wrong though, when the dog sleeps on me.
Wow, you’re the anti-me! I hate wearing shoes and take them off immediately whenever I can (which means in class under my desk, and in restaurants under the table–sue me). I also sleep naked except when it’s really cold, when I’ll wear a flannel pajama top to keep my arms warm. I lurves me some bein’ naked. I walk around the house naked or in just a tank top* all the time.
*windows, ya know.
I’ve slept in the nude before, but I feel most comfortable in a worn T-shirt and underwear.
And now I desperately want a nap, and I still have papers to do for tomorrow, and I despise you all. Really. 
I sleep in boxers and usually wifebeaters. I don’t mind sleeping naked but not all the time because quite frankly I don’t like the idea of my junk and butt rubbing all over the sheets (I maintain good hygiene but still).
You have a model of undies with an integral butt-plug? :eek:
Count me in with the nekkid clan.
When I’m sleeping alone, I’ll usually wear underwear. If someone’s with me, I prefer sleeping naked - I like the feeling of someone’s skin against mine.
When alone, I wear men’s gym shorts and a tshirt usually. Roommates and all.
With my boy, usually naked or just underoos.
Shorts and tshirt in summer, sweats and tshirt in winter.
Jama pants in summer if its humid, I hate to feel all sticky. 
Cheers,
G
Naked ONLY if someone is spending the night with me (he needs complete access, you see). Otherwise, currently, I wear big floppy knit boxers. I just feel more comfortable with them on although, they expose almost as much as when I’m naked.
FYI, us kids were taught that we MUST wear both pajamas AND briefs to bed. I suppose that’s why I’m more comfortable with something on.
Bob
Usually in pajamas. My arms get cold even in the summer, so I always wear at least a top. I also don’t like how it feels when my legs press together and stick (this is the same reason I don’t like to wear skirts without stockings). I’m much more comfortable in a loose pair of PJs most of the time.
Just a t-shirt, please. I hate the feeling of laying on my hair, so I don’t go naked 'cause of that.
I can’t STAND having anything on my legs ('cept a blanket), so definitely no pants. Undies are borderline. Sometimes I wear them, usually I don’t… gotta let things breathe, you see. I sprawl, and anything below the waist just gets in my way.
Been sleeping naked since I was 15. Unless I’m a guest somewhere, and then I’m slightly uncomfortable all night. I can handle wearing a thin shirt, but any bottoms bunch and leave wrinkles and twist around me and it’s irritating as all hell.
I see. And what did the neighbors say when they saw all of the nightwear you tossed out the window?