If you're a Hacker News user who wants an Android phone, you probably shouldn't be buying anything that isn't Nexus-branded. The Galaxy Nexus is great, but there's usually a new Nexus each winter.
I'll probably buy my first Android device when they do. As a long-time iPhone user, the Android device market has been utterly bewildering to me. It took me a while to discover that the Nexus handsets were the only ones that (a) offered the naked/unskinned Android experience and (b) received Android updates from Google directly independent of network provider schedules (I think?).
Allowing handset manufacturers to skin the Android UI and bolt on their own wacky additions, then letting carriers determine when updates are provided has diluted and confused the Android handset marketplace, in my opinion. As an end-user, it is not just a choice between hardware; I also have to work out which manufacturer has 'reinterpreted' the Android UI, and which carrier will let me update the phone. (And I still haven't worked out how OS updates work if I buy a second-hand device off contract.) It can be wonderful to have such choice, but the Android phone market is far more confusing than the iPhone one.
[1]: http://www.theverge.com/2012/5/15/3022682/google-direct-sale...
This bit is the problem. I don't jailbreak a device before I am ready to throw it away. I've seen too many issues with non-official hacks of various sorts. Nothing major; just rough edges.
They even provide an official tool for rooting.
There's pretty much no chance of bricking your phone, and if you go with a stable CM build, you shouldn't have any problems.
http://get.cm/?device=i9300&type=stable
... while the Galaxy Nexus has already gotten its OTA update. Closest I've found is the SuperNexus ROM, but even that's still glitchy.