I have had good luck with whitewater canoeing stuff mostly - This may be pretty unknown to people who don't travel in whitewater circles so I will explain as best I can.
White water canoeing is a lot like 4wd camping - You have a lot of room to bring stuff, and you usually want to keep your stuff sealed as either water, or dust, mud, whatever will get into your stash, end you don't usually roll, but when you do you, it's bad
The blue plastic barrel trick is perfect. These are used in industry for carrying non-toxic stuff like Silica powder usually, they come in different sizes, They are tough as nails, super light, cheap (20$) if you get them used, and they are pretty well sealed. The also make a great table/seat. They also double as a great water container if the going gets rough. I throw em on the roof, they are light and bulky.
I keep a couple Peli cases but I find them to be heavy for the size. Usually reserved for expensive stuff only.
Dry bags - I have a few dry bags - these are rubberized canvas bags that roll up at the end to seal - they are super handy for clothes and other soft stuff, plus they are really strong so you can use them for packing between the hard stuff to minimize the banging. MEC has em for cheap.
I hate ammo boxes, they go bang and they are heavy, but they are freakin handy. I keep logging chain and recovery gear in two small ammo boxes, mostly for non-expedition factors (I can switch em from truck to truck in the winter).
Wannagin, Wanogon, Waanagon, Wahnagin, I dont know the spelling. Big plastic box for cooking stuff. Kind of pricey but tough as nails, like 1/4" polycarbonate type stuff, great cooking surface, and I can use it for all my camping. Got it from Trailhead, specialized whitewater canoe place, but they are around. Kind of like rubbermaid on steroids.