I would kinda like it if, in future editions, the rules didn't make weapons different, and instead your feats did.
For instance, every two-handed fighting style (whether it's got two swords, one big sword, a spear, whatever) would deal 1d10 points of damage plus twice your Strength bonus. Every one-handed fighting style (basically anything that would let you use a shield for defense) would deal 1d6 points of damage plus your Strength bonus. Every attack made in a grapple, or made by a reach weapon used in close combat, does 1d4 points of damage plus your Strength bonus.
Size doesn't matter. Things no longer get size bonuses or penalties to attack rolls or AC, so the only things that change are Strength bonuses, and reach.
For weapons like whips and spiked chains that can be used either close or at reach do damage one die size lower for every square of reach, so a spiked chain (10 ft, two squares) is a two-handed weapon that does 1d6 (two sizes less than d10). A whip (15 ft, three squares) is a one-handed weapon that does d2 (three sizes less than d6). And yes, a whip can harm anyone, even someone in armor. Just imagine that you're wrapping around their leg and yanking, causing some sort of tendon and muscle damage.
If you have Martial Combat Proficiency, increase the damage die by 1 step.