I switched to buckwheat pillows a few years ago and I've been a fan. It's a really interesting texture that you can move and shape really easily, but then when you apply pressure to it, it firms up and holds its shape. So, you get a really supportive pillow that's molded to your head and neck (For reference, I'm a side sleeper). The only downside I've noticed is the filling degrades relatively quickly, and after about a year it loses a lot of its volume and doesn't hold its shape as well, so you'll need to replace it. The bright side is that it's fairly cheap, and entirely biodegradable.

Eh, I've tried all of them at least once.

For my money, shredded memory foam is the best. It isn't perfect, but I've had the best balance between comfort, durability, ease of cleaning, and cost.

Buckwheat was good at support, and stayed fairly cool, but the breakdown and difficulty of cleaning made it a problem. It just doesn't last as well. Only thing that was worse in that regard was feathers. Feathers get ruined faster than anything else I tried.

Pillow cases, I'm a cotton fan. High thread count cotton has the right balance of softness vs smoothness. Too soft, and you end up with bunching and wrinkles as you move. Too smooth, and you end up with your head moving too easy but your hair not moving well.

Polyfill sucks for everything except ease of cleaning.

Cotton batting is about the same as polyfill, but not as easy to clean.

Solid foam is just begging to sweat heavy, and damn near impossible to clean well. Plus the durability is iffy.

Pillow cases, actual linen isn't bad, but tends not to be as comfy as cotton. Silk is way too smooth. Satin is just uncomfortable. Synthetics tend to run hot, even though they feel nice. Knit cotton feels the best, but damn does it fall into poor condition fast.

I sleep on a buckwheat pillow. It's pretty decent, and as a bonus it guarantees victory and the extermination of your enemies in every pillow fight!

That looks more like dirt than buckwheat.

Silk pillow cases are awesome! I've upgraded my linens in the last couple of years and silk pillowcase are probably my favorite splurge. I have two and i try to steal my husband's so i can have one on the bed and one on deck for change day.

I have the Purple Harmony pillow. It took some getting used to, but yes, it's worth it. I use a silk pillow case because of my hair: 4C hair is dried out by cotton and people recommend not sleeping on it as a result. My hair has never been longer though, so I think that's true too.

I use down feather pillows, they are easily customizable but they can go "flat" and hard in the middle of the night. Putting your head down on a freshly fluffed one is utterly sublime, though.

I have fallen in love with bamboo rayon pillowcases, (aka modal, aka tencel, aka lyocell). They can be extremely soft and smooth like silk but are much hardier, so you can wash them like normal laundry.

Buckwheat pillow with a thick flannel cover. Belly sleeper and my pillow travels everywhere I do.

Buckwheat, in my opinion, takes a good 6 months for it to be properly broken in, but once it is I have a good couple of years of amazing sleep.

I love my husks in a sack. I also use a foam pillow here and there, tried a hyped up shredded foam pillow but hated it, solid foam is the way for foam imo. Never tried silk pillow cases but I do enjoy cotton.

Yes. I can't talk about buckwheat in particular but, considering your face goes on it, I consider a good pillow case more important than a good set of sheets.

Silk pillow cases are really useful to people with curly and coilled hair! Cotton pillow cases makes that kind of hair super frizzy, but a silk case can be softer on the hair meaning your curls are still intact in the morning :) Often people will use a silk wrap or hear wear instead of a silk pillow as they can ve cheaper and keep your hair more secure. It's personal preference but can really help reduce frizz! Hope that helps

Edit: bloody spelling

I'm enjoying a kapok as well as a down pillow. Only natural for me, nobody off-gasses on my face.

real silk pillowcases are just too slippery for me (and you have to wash em in a bag) so I stick with cotton.

Down feather pillows are $$$ but great if you like them soft and fluffy. Get support by fluffing and kneading.

I really like my water pillow.

In modern times it's important to keep in mind that the stiffness can be different independent of the type of filling.

That is, I'd pick filling primarily by allergies, and then by personal preference. They all feel marginally~moderately different, and some you'll just associate with "nicer". For me personally that's memory foam, for example.

Then independent of that, pick a stiffnes and, importantly, a shape that works for you. I sleep worlds better on a very stuff shaped pillow that perfectly matches my neck size and length.