In the winter, DH and I are pretty ridiculous. Our bedroom is colder than most of the house and we like to be warm when we sleep. I sleep in pajama pants, a tshirt, and a hoodie/sweatshirt on top. DH sleeps in a hoodie too.
In the summer DH will sleep in just his underwear, I usually wear a tshirt and some pj capris.
Right now I'm wearing flannel pj bottoms and a long sleeve t-shirt. If my arms aren't covered I get SO cold. We have air conditioning in the summer so I still wear a similar sort of thing except maybe not flannel bottoms.
If DS is home, which he usually is, I wear a t-shirt and shorts or sleep pants, we still co-sleep most nights. If he isn't home, which doesn't happen often, I sleep in the nude. I often have weird dreams because I am wearing clothes that are getting pulled one way or the other while I am sleeping.
Whatever I was wearing as I fell asleep. If I spent the day in pjs, then that... Or scrubs or whatever!!