For the most part I accept that - every so often in a published work of fiction - there are going to be typos. Authors, beta-readers, editors, line-editors, copy editors are only human after all. Every so often a mistake is bound to creep through.
And I'm hardly the queen of grammar and eloquence to be standing on a pedestal casting stones - though I will stand there and mix metaphors. :)
But on some occasions - specifically two - it really does annoy.
1) Getting the name of a character wrong. I don't think anything knocks you out of a story quicker than if characters start talking to another character who isn't currently present or worse who died earlier in the story. There's a moment of uncertainty - What's happening? Have I suddenly switched genres to ghost story? - Followed by the realisation oof what's happening and then having to go back and unravel who is actually saying what.
2) The substitution of a word which sounds the same/similar to the word that the author intended to use, but because it's a real word it's not picked up by spellchecker.
Sometimes the meaning of the sentence is changed very little and you can understand how it wasn't picked up in the editing process. Sometimes however, the meaning of the sentence is changed completely.
The famous use of penile (relating to the penis) when it should have been penal (pertaining to or involving punishment). The author was referring to incarceration.
So typos - unexpected, unavoidable. annoying? And have you come across any real humdingers that stick in your memory?