My favorites:

Cheap nylon running shorts if the weather is warm, bugs minimal to non-existent, and I'm staying on trail. Light and most comfortable option.

TNF convertible cargo pants. I wear these when I have to travel a lot to get to my destination. I need a new pair, they are well worn and patched.

5.11 Tactical Taclite Pro pants are my choice if I'm bushwhacking. They hold up really well for serious off trail use. No patches or tears on mine yet.