Mine is OOO for Out Of Office. I always misread it in my head like a ghost and it takes me a few seconds to process. It also doesn't translate to speech—you have to say the whole thing.
Interested to see if others have similar acronyms they beef with.
Not me but my spouse hates recursive ones, like GNU. Hates them so much, active vocal expressions of dislike. Anyways the setting I'm making is filthy with recursive acronyms for no reason.