I'm trying to collect all the uniques in the game and sometimes it's frustrating to see yet another Ladon's Maw, Eye of Horus or some other unique item that always drops and not get the ones you're looking for. Strangely enough, I still don't have The Citadel while The Bulwark (both part of the same set) dropped a gazillion times. I find unique swords to not drop very often really.