THE WORST was while walking up to a theater some random idiots walking past me had just gotten out of the movie I was about to see and were talking amongst themselves dropping spoiler bombs left and right. It was unavoidable... I couldn't
not hear them.
Another bad one was when a spoiler became a meme for a movie I was waiting until it was on DVD to see rather than seeing it at the theater...
snape kills dumbledore... like wtf who makes that a meme
Stuff like that... If it's written usually I can just barely start skimming it then stop myself and try to forget what I saw. Usually if I'm not really into something yet I won't remember specific names so it's not too bad if I accidentally see something sometimes as long as I stop reading right away.
The really bad ones are the jerks that don't even put shit in spoilers and just openly talk about it in threads like part of the normal conversation and you just read it without even expecting anything and then it just hits you out of nowhere.
Or like telling a friend you're starting a series they recommended or something, then after awhile if you're talking about it they might be like "Oh, are you at the part where ___ yet?" with the blank being some massive spoiler...
Oh another one I hate is movie trailers that singlehandedly spoil the entire g'damn movie.