For me the most annoying bugs are the chain casting npcs which mainly appear in missions, theres a host of other problems with missions also. And the HUGE memory leak, PLEASE PLEASE PLEASE put more attention into this, it makes the game freeze up after 10mins with the graphics turned up all the way, which is why i play with the graphics turned down, which really SUCKS, but even then after an hour or two the game just freezes, usually while trying to zone.