I just posted this in another thread, and it seems just as applicable here. And no, I don't work for Outlier.
http://shop.outlier.cc/shop/retail/4season-og-pant.html
I know these are expensive, but much less so when you consider:
1. They're so comfortable on and off the bike (temperature, stretch)
2. They're virtually waterproof.
3. They're virtually stain proof.
4. They're stink proof (rarely need washing; one pair will be enough unless you want to mix it up).
5. They look decent.
6. They show no apparent signs of cycling-related damage such as crotch erosion.
I love mine and pretty much only wear them.
Everything else--socks underwear and sweaters or t shirts--merino. Although Levis just started to sell a treated cotton commuter shirt, and Outlier has those too.
Pants are most important.