Hacker News Reader

And the other side of that coin, if you just want the articles without comments and fluff, http://skimfeed.com.

To make things clear, Ypander doesn't alter the HN visual design in any way. It just provides a faster way to use it.

Didn't know about this - the comment collapsing alone is worth it. Thank you to whomever made this!

If you just want the comment collapsing enhancement, there are a couple of Chrome extensions that do this, and if you want it in Firefox, there are a couple different bookmarklet implementations that will do it.