The only truly water proof pants I have other than rubber rain pants are Cabelas dry-plus soft shell pants. You can sit on wet ground with these, for a while anyway, and stay dry. Soaked underbrush and raining.. you stay dry. They'd be no good in warm temps though they'd be too hot.
Normally I don't worry about waterproof and get by fine with water resistant or at least quick dry. For nice thin very light hiking type pant I've got 5.11 both in tactical and hiking pant style. Same material extremely comfortable, beads a bit of water off but they will get wet. But will dry in a snap given a chance. Next step up I've got some Kuhl soft shell pants that are a lot more water resistant and almost as maneuverable. If its not wet out and not too much gymnastics going on often its plain old Carhartts.
