I had a fuckload of super soakers!
My favorite is easily the super soaker 100. Before they needed to get all crazy. The 100 had the perfect combo of water conservation/storage capacity as well as needed power/range.
I had some of the later stuff, but even the 1000 used up too much water too quickly. I used to have the double barrel one with the backpack. It used water like a mother fucker.
We used to have attack/defend battles and mount the larger cannons to our fort. We'd use them for defense only.