I use the round tins (GL PEASE, C&D) for storage of hardware, nuts bolts etc.
The rectangular I use for tackle in the tackle box.
Any really cool tins I give to the grandkids to store "treasure" in.
Neatest tin I ever saw is the tin that a tobacco called "Blue Train" came in. Didn't care for the tobacco so much but the tin is beautiful. Dark blue with a picture of the blue train steaming across the veldt.