For me, the biggest reason is the community and the people that hang out on HN. I mean how many places can you get Alan Kay to do an AMA of such high quality as this:
https://news.ycombinator.com/item?id=11939851
Other reasons are simplicity and speed of HN site that makes it a breeze to only focus on the content. No flashy stuff.
I find myself coming here almost everyday because of the level of quality in the content. I always leave with something new. It's a great place full of smart minds, civil discussions, and lots of knowledge.
I actually thought about this the other day. Whoishiring every month was the only real reason I could come up with.
I like seeing what tech trends people are discussing and what people are working on (show HN)
Interesting stuff on here. Also found my current job (which is awesome!) here via whoishiring :)
For the comments, and ask HN.
The level of discourse at HN is, in my opinion, the best on the net. I value the contributions of the commenters here, and that's unusual for me anymore.
Content. And no "modern" web UI bs with ads that bring a super computer to it's knees.
Because reddit is blocked at work.
ShowHN's that make it to the front page. Space news.
Read? I'm just here for the pictures.
To pass time during a long jenkins build...
Mostly addiction
Typically I resort to HN as a forum of modern scientific knowledge and young chaps and old chaps trying to make cool stuff happen in the world. It's really not about venture capitalizing or even making tons of user conversions for me, I have no tech products that I sell and I have a huge skillset. I'm interested in the furthering of human knowledge and HN is pretty close to what slashdot used to be for that.