Fiber/fabric: What’s your favorite?

I definitely caused some confusion when I asked someone what his favorite fabric is. Although I am a fiber crafter, I had opinions on this before I ever began the hobby. Some of it may be because I have sensory issues that have me preferring soft, natural fabrics. There’s also the matter of many natural fabrics being easier to care for. Many polyester-esque fabrics have complicated washing instructions like: Cold wash gentle cycle, lay flat to dry, no iron, spin around three times under a full moon with a young chicken, etc. (For this post, I will be using fiber and fabric interchangeably, since fibers make up fabric, and materials composition will generally apply to both.)
To be sure, polyester and other synthetic fibers do have their place! One of my favorite yarns, Juniper Moon Farms Cumulus, is a soft, fluffy cotton blend with just a touch of nylon for added strength. Polyester fabrics can also have a practical use, such as when you need a blanket that will keep you warm on a cold evening. Synthetic fabrics trap heat better, keeping you warmer.
A lot of crafters love animal fibers, but I don’t use them, myself. I do know that alpaca wool is very soft! All types of wool can keep you warm, even if it gets wet. But as someone who is allergic to animals (sob!) I avoid these fibers to be on the safe side.
So, what do I think are the best fabrics? Cotton is a classic mainstay, of course. Bamboo is a lovely, soft, sustainable natural fiber. Some fibers, like modal and Tencel/lyocell, are natural fibers with a synthetic process. So they straddle the line between natural and synthetic. Some polyester yarns, like Bernat Blanket Yarn, are soft and fun to work with. It’s nice to have a yarn that doesn’t split!
What fibers do you like best? Does your opinion change depending on what you’re using it for? Leave me a comment with your thoughts!