I deliberately left out the hard shell (which would go over my Montbell Thermawarp or fleece if it's both cold and raining). The absolutely perfect hard shell, of course, would be 100% waterproof in an all-day downpour but still extremely breathable at 65 degrees. It would also have to weigh 12 oz. or less for rain jacket and pants combined. I don't believe such a thing yet exists--I certainly haven't found it. So in mild weather I take my Frogg Toggs jacket (which is very breathable and holds up to at least a couple hours of rain). For colder, wetter conditions I recently acquired a Brawny jacket and pants from AntiGravity Gear, which (since they're not breathable) I bought in a large size for more ventilation. Neither is perfect, but at least they're light. Actually, if the temp is 65 or higher, I've found it's better to strip down to nylon shirt and pants (which dry very fast) and just get wet, wearing gaiters to keep the water from running inside my boots.