So, quick question: which canisters from all of LEGO's constraction history (from Throwbots/Slizers to Roboriders to BIONICLE to Hero Factory to any I'm forgetting right now) were the best and the worst in your opinion?
Myself, I can't say much before the BIONICLE era, but I can definitely point what I believe was the worst from then on: the Toa Mahri canisters. Once they were open, they were practically unusabe as storage, which defeats the very purpose of a canister, and the armature/sub configuration made very little sense as a set (where was the floor?) or in-story.
The best, on the other hand, it's hard to tell, but I'd probably choose the Toa Mata's original canisters. They were simple but functional, the rotating cover revealing the different Toa and iconic marketing scenes made for great advertisement, and they could easily incorporate not only one but two in-story elements: the Toa Canisters, obviously, but also the Suva with the lid - which also made an effective subtle collecting nudge to complete it with more masks and Toa heads.