CETSE stands for "Collected Editions That Should Exist."
Here, I'll look at series/stories/characters/sort of related things that (to my knowledge) have never been collected (either properly or at all).
For example (one that I will devote entries to in the future), there has never really been a comprehensive collection of Green Goblin stories. From what I can tell, the only collection dedicated to Green Goblin I (Norman Osborn) is a small TPB from 1995 that only includes a few of his storylines (but not even his 1st appearance!).
So, in a CETSE post, I'll lay out what should be collected, why it should be collected, and how it should be collected.
Suggestions are always welcome.