The first thing I read out of high school was "Human, All Too Human" by Nietzsche.
My 11th and 12th grade English teacher was that one teacher you never forget for me, and he recommended I read three things for college (he usually recommended Shakespeare, but I was already milking that for all it was worth already even back then, lol)--
Nietzsche, Kierkegaard, and the Russians.
He said to read those, and I'd have an advantage on others in college...
And I think he was right.
Nietzsche's the stereotypical college go-to for kids trying to sound smart (case in point :p ), but he's a good example of both what do do and what not to do in writing and argumentation, I think...he's very good at drawing readers in and inverting ideas and being controversial (hence why he's so beloved in college) but a LOT of what he says...apply logic to it, and you have a problem.
Kierkegaard's Nietzsche for people who want to go with the less obvious choice or make a Biblical reference.
And Mr. 12th grade teacher, Mr. Holt, was right--
Aside from the occasional "Crime and Punishment" name-drop, I've never heard any student mention a Russian author, so that's one whole group of authors I've read that peers at my state-level college haven't.
Doesn't make me smart (my posts here attest to that) but it turned out to be good advice...and looking back at that first post-college book now, it's a wave of nostalgia, for good and for bad...
Meaning that if I sound like a pretentious shit NOW, you shoulda seen my crap here back then! (And to those of you who were there for that...hey, at least the Ubermensch references have diminished, right?) :p