It always depends on your *other* gear, in other words, it depends on what stats you're missing.
For example, I used to have huge mana issues so I stacked spirit more than anything else. At that time, Chelley's Staff of Dark Mending was perfect. Now that my gear is all lvl 359 with one 372 piece, I'm fine on mana in most fights but I found I was lacking throughput so I switched to a main hand/off hand combination which together has a good bit more intellect than the staff. So, weigh your options, see what stats need boosting and get the weapon that has those stats. We don't actually *use* our weapons after all, we have them solely for their stats, so there is no "best" option per se, only "best for you at this point in time".

