The Paladin's Shield.
Me and my friends were fresh in the Hardmode dungeon after killing Plantera. We did so well in the boss fight because our tank recently got Turtle armor, which also took quite a while to get. So, when we initially entered the dungeon, we brought over a golden bed we got in a pirate invasion. So, me (the ranger) and my buddy the mage sat back and sprayed our most spammy weapons, while our tank got destroyed over and over by the hordes of infernal armor skeletons. Every time we saw a paladin we trapped it in a hole and shot it with golden shower and the megashark for whole MINUTES before they died. Also, the ankh is pretty hard to get for me in my SP world.