EarthBound is full of all kinds of hilarious weapons, but I think Shadow Hearts: Covenant's Frozen Tuna takes the cake. Joachim's awesome enough as it is, but that whole event was just surreal. What a giant, frozen tuna was doing in the snow outside the Czar's palace I'll never know, but seeing Joachim bludgeon enemies with a giant fish... there's nothing that beats that.

Well, that, or Ammy taking a leak on demons in Okami. At any rate, my vote goes to "Other".

@Skyblade: Cuuuuuuuuuuuuuuuuuuuuuuute!