I like super obscure achievements that aren't documented at all. Like, your weapon and armor just broke but you're in an easy area so you just keep grinding, trying to find that rare loot (or whatever). Suddenly, you get an achievement, "Naked Brawler" π
You check the wiki and that one's not in the list π
I remember getting an achievement for something like, "Last Light" in some game where I ran out of torches in an area where you take severe damage from darkness. I got the achievement when I lit that last torch, very close to the end of the area.
It wasn't documented anywhere! I posted about it to the game forum (this was back when forums were the primary place to talk about such things) and no one had seen it before.
Like a year later, the community finally figured out the sequence of events necessary to get that achievement and it only gets awarded to characters who are too far in to make it out before the torch goes out and those that read a very specific, obscure book in a starter area.
"You read the bookβ½"
"I... Uh... Read all the books. Doesn't everyone read all the books at least once?"
π€£