Ask HN: Timeless/Classic Engineering Essays?

One of my favorite parts of HackerNews is when old (for some definition of old) blog posts and essays are resurfaced and discussed.

I imagine that in the 30 year history of the internet a lot of really great pieces have been written about software engineering, technology, etc. But I worry about those pieces being lost to the winds of time. And, more selfishly, I also just want to read them.

What's your "oldie but goodie" piece that impacted you or that you always share with people?

PS. Not limited to internet essays, of course. Pre-internet essays are also welcomed.

PPS. Bonus points for links to repositories or sites that aggregate said classic essays.