Vendor trash is a weird idea in lots of games. There are usually even specific categories of it; any gray item in World of Warcraft is explicitly meant to be vendored and forgotten, it’s disposable trash. Except that there are equippable items in that tier. There are green items in Star Wars: The Old Republic that are more worthwhile to just vendor than bother selling or using. I know that Blue Yarzon Legs in Final Fantasy XIV have an actual function, but I’ll be damned if I can recall that function beyond clogging up my inventory.
The idea of vendor trash is that some things you just want to sell at vendors instead of futzing about with auctioning or whatever, but sometimes the items you’re supposed to sell are things you actually want to keep for whatever reason, and sometimes the stuff that’s theoretically valuable is actually worthless. So what do you think, dear readers? How useless does an MMO drop need to be before it’s vendor trash? What can you think of as the most egregious examples of theoretical vendor trash that isn’t… or theoretically useful items that are vendor trash?