Hope's Airwing so I can figure out how he manages to put it in his pocket. Seriously! I'm sure we all like to make up silly s**t about where they put all their potions and how they "walk into" each other and other gameplay discrepancies like that, but Hope literally puts his Airwing into his back pocket at the end of battle!
Freya's "Kain's Lance/Spear"
Kain's "Abel's Lance"
Not religious.... Just a combination that says, "WHY! not?"
and I would probably rip the ruby jewel out of Amarant's "Rune Claw"
<.< (Black Market yeah?) Dyne's arm w/ the grafted gun still. "WEEEEEEEE!" (flings the arm around and joints retract on the trigger)
And lastly, the "Assassin's Dagger" don't really need to reference which games it's from. Considering it is in a few and it's main status effect is to cause instant Death. I just don't remember the percentages except for the fact it is almost constant (in most of my cases) in Final Fantasy IV T.A.Y.