Monstrous Television just blew my mind with this elegant mechanic for AD&D:
Characters wielding one handed weapons deal damage equal to their hit dice. Two handed weapons (or one-handed weapons held with two hands) increase the die by one size. "Light" weapons (daggers, knives, spiked gauntlets) and improvised weapons (broken bottle, fire place pokers) decrease the dice by one size, as do all missile weapons. Anything dealing less than 1-3 damage rounds up to that point. No change based on the size of the opponent.
Read the whole thing if you want to see the mathematics involved. I think this solves a lot of problems. It's never been clear to me that adding excessive "crunch" to the (ever expanding) weapons list ever did much but promote power gaming. Nobody chose to have a bastard sword because of their character concepts, did they? It was about maximizing damage.
This, on the other hand, simply makes the character choose light/one-handed/two-handed. The rest is handled by the class HD. Nothing else to know, really.
I think this might be my next house rule.