Linen. Always. But they are getting hard to find and expensive.
Needles & Grooves
TrainFan73
YoHabloEspanol
Is linen equal to cotton?
TrainFan73
No.
www.peacockalley.com
Linen vs. Cotton: What is the Difference? | Peacock Alley
When it comes to luxury bedding, the fabric of the sheets, duvets, and pillows you choose, truly makes all the difference in the world. The sheets, especially, since you lay between the two, should be made from the most comfortable fabric and materials available, which most people consider to be...
www.peacockalley.com
TrainFan73
Linen is made from flax.
TrainFan73
A linen cotton blend is fine.
YoHabloEspanol
Gotcha! Thanks for the link. I was unaware of the difference.
TrainFan73
People refer to linens which is sheets and towels and stuff.
blenoxsmith
just here to say congrats on a king size bed! partner and i made that shift in June and it's a friggen dream. i don't even know what sheets we have, sorry, but the SPACE shift is unreal
NateOEB
I like the bamboo rayon ones from mysheetsrock, they're great if you're a hot sleeper.
YoHabloEspanol
We had a Full size bed with the wife in our first flat, 10 years ago. We moved that bed to our house. Then the baby arrived, and I had to sleep in an air mattres on the floor. He never used his crib. We got the King on new years and the baby sleeps between us, and he takes up most of the space.
TrainFan73
I didn’t really like the king until new kid came along. I liked the snuggles before…
Memo
I just grab whatever feels the softest at Costco and I’m always comfy! 
DevonJD
If you have a home goods by you, look for UGG sheets. So soft
Sebastian
Bamboo sheets
nolalady
I also have to recommend bamboo sheets. They are really nice sheets if you are a hot sleeper or, like me, live in a warm climate. They are soft, breathable and cool.
TenderLovingKiller®
Thread Count is Bullshit. Just make sure it’s 100% cotton.
TrainFan73
thread count does seem to correspond to softness in cotton sheets.
TenderLovingKiller®
I prefer cotton but I am sure Linen and bamboo is good too. Just make sure they are 100% natural fibers.