What is the best material for a cool/warm weather hiking pant?

I did a lot of hiking when I was young and just got all new gear and my wife and I are planning many trips backpacking/backwoods camping and I want to have a few good pairs of hiking pants. Just not sure of the best of material. When I was young all I wore were jeans. I know there are many new materials that will work a lot better. I don't want to pay $100 for any pair of pants. I do like having some that would turn to shorts. I can just take any pant to be altered after the fact. Just seeing many different kinds of material and not sure what is the best. I do not like the poly plastic feeling stuff. Other than that I am game. Thank you