1 Sea to Summit dry sack for clothing
1 S to S ditty sack for small incidentals (ex. I put the daytime contents from my pockets in this ditty sack while I sleep)
1 dry sack for my sleeping bag (I think its an old Granite Gear compression dry sack)
1 large OR dry sack for hanging my food (bear bag); has minimal pack straps to double as a day pack to carry stuff on very short excursions away from camp
1 non-dry sack for my tent
1 quart zip lock for the maps and compass
1 gallon zip lock for my food
1 quart zip lock for my trail snacks

I think I also store the fuel line for my stove in a zip lock, and the output (clean) line for my water filter gets one too.

A box of zip locks at Costco are very inexpensive (I think the current deal sells you 2 boxes ea of quart and gallon sizes for ~$12-14); and I've used my REI premium on various dry sacks the past few years.

I don't weigh items I carry on hikes - total pack weight is about 25 lbs for a 3 day hike.

I am a little bag crazy - I hate hauling out socks and sweaters and food and every little thing to get to a Chiclet at the bottom of my pack, then repacking. I'd rather bring out 3-4 sacks to get to the thing I need, then pop them all back into my pack. the only odd thing I've found it that packing dry packs leads to some voids in your pack, but if you pack well it doesn't get too weird. And every sack that contains things I want kept dry has to be sil nylon or some other reasonably waterproof material.

Rain or river water has a way of finding me on the trail - I've never regretted carrying things in waterproof dry sacks even if the non-waterproof alternative is half the price.