Supposedly, carbon nanotubes.
I have several microfiber "golf pants" from dockers that are over 10 years old and worn weekly and still look. Crazy material.
Wool, though prepare to dry clean. But, they tend to look and wear better than anything else in my opinion.
microfiber doesn't look tough but it's silky smooth, tough and breaths very well. They are by far my favorite and they are also very light and supple.
Wool all day. Dry-cleaning is not ideal, but if you wipe your ass like an adult and don't sweat profusely, you should only have to send them in around once a month (depending on your pant rotation).
My problem with microfiber is they seem to snag on everything and then it looks horrible with strings sticking out. Especially if you wash them in a machine with everything else, something will catch on it and screw it up.