Umbranus |
The condition I come across most often seems to be fatigued. But I guess there are some paladin guides around which suggest mercies.
I would aim for conditions which you can remove when you are the one who is afflicted. So nothing that keeps you from using lay on hands and nothing you are immune to.
That means no shaken and no dazed, for example.
Rynjin |
IMO Fatigued is probably the best from the 3rd level list.
Also IMO the 6th level list is pretty bad. Take Sickened instead and then Nauseated, (since those are some pretty debilitating conditions you're not necessarily immune to), and Blinded to cap it all off at 12th.
From there it's kind of a matter of preference or circumstance.