I think there are quite a few commendations that seem out there; as well as some GE tasks. But, generally we are not required to complete them but it still bugs us completionist type. The one that has taken me forever to get has been "Destructive appetite" largely because it is bugged and is not cross-characters. Also seems to take forever to refill the stuff other than the two ammo types at the base. Lately, just to get it done, I have dropped to WT1 / normal, ran Consulate as fast as I could (the first room) reload, repeat. I am now within a hundred or two.
I remember one GE where you had to kill 150 riker bosses (IIRC), that got really old.