Boy, I wish someone had asked this before.

The best posts are ones that say something surprising (e.g. not just a reporter writing a routine story about a familiar topic), and say it in a convincing way, with depth of argument, and numbers, if applicable.

Posts about how to do things oneself, and how things work, tend to be particularly appreciated. This is an audience that likes to know the details.

Posts don't have to be about hacking, so long as they talk in detail about something novel or surprising. Though arguably anything that talks about the internal details of how something works is about hacking, in the broader sense.

http://news.ycombinator.com/item?id=411994

http://news.ycombinator.com/item?id=406885

http://news.ycombinator.com/item?id=418776

http://news.ycombinator.com/item?id=414330

http://news.ycombinator.com/item?id=418329

http://news.ycombinator.com/item?id=414226

http://news.ycombinator.com/item?id=414502

http://news.ycombinator.com/item?id=418098

The author, Steve Friedl (brother of Jeffrey Friedl, of regex fame[0]), is not only a wizard but also an inspiration; this article had a huge positive impact on me early in my career. Here are two other times it generated a number of comments on HN:

2008: https://news.ycombinator.com/item?id=411994

2010: https://news.ycombinator.com/item?id=1430968

[0] http://regex.info