This is always a great way to add some depth and personality to a story. Though it HAS been done ad nauseum in nearly every forum, past and present.
It is still worth saying that the discussion of sentient items with a possible agenda, always reminds me of this little poem.
"Three Rings for the Elven-kings under the sky, Seven for the Dwarf-lords in their halls of stone, Nine for Mortal Men doomed to die, One for the Dark Lord on his dark throne In the Land of Mordor where the Shadows lie. One Ring to rule them all, One Ring to find them, One Ring to bring them all and in the darkness bind them In the Land of Mordor where the Shadows lie."
J.R.R. Tolkien : LOTR
A seemingly sentient item with a questionable and visibly suspect agenda. Classic.