3. Most Intricate:
a. By far the most intricate is the Terra Blade. You need 12 Hallowed Bars, 40 Crimtane/Demonite Ores, 12 Jungle Spores, 60 Hellstone Ores, 15 Stingers, 20 Obsidian, 1 Muramasa, and 3 Broken Hero Swords. You also need a Mythril/Orichalcum Anvil, a Hellforge (or higher), and a Demon/Crimson Altar; in order to craft everything.
b. Though considerably less intricate than the Terra Blade, the Optic Staff does require a decent amount of components. It is also a very versatile weapon. Spazmamini uses melee attacks, and Retinamini uses ranged. You basically get two different minions for the cost of one (and the minions are miniature versions of The Twins in their final stage, which is pretty cool).