Here's a thought about two-handed melee weapons, like the great sword. Like some people, I give a +1 attack bonus to anyone fighting with two weapons, rather than two attacks; the rationale is that you're trading the +1 defense you would get from a shield in your off-hand for a +1 to hit. Since the common argument about using "all weapons do 1d6 damage" is that it makes using a two-handed weapon a drawback rather than an advantage, why not give the same +1 attack bonus to great swords and the like?
This is better, for me, than increasing the damage of a great sword. Consider: an ogre does 1+2 damage. If you increase the damage of the great sword, you have to ask: is a man with a great sword equivalent to an ogre? If not, the most damage a great sword should do is 1+1. That's considerably less than most proponents of "variable weapon damage" would prefer.