I personally find rain pants to be too hot, even the breathable kind, and too loose - they bunch up and catch on things. I find them much more uncomfortable to ride in than plain old tights. I don't even have waterproof tights, just ones that will stay warm when wet (so just no cotton). Tights would also be less bulky to carry and more versatile than rain paints, when what you can pack/carry might be limited. I don't have a favorite brand, but I prefer tights without a chamois so that I can layer them over my regular shorts.

I really don't worry as much about waterproof, except for my feet, when I ride in the rain. Even breathable rain gear holds enough body heat and moisture to make you sweat and get drenched, so I find it better to just go for the warm when wet option in the first place. I prefer softshells to regular rain jackets. I do recommend waterproof booties, they'll keep your feet pretty warm and dry for at least a few hours.