So... further thoughts.
1) Crits as Maxed Damage Values
When you crit, you max out the damage of your attack, then roll it a second time and add that on top. This ensures that crits are meaningful and strong. No more rolling minimum damage on a critical hit. It also makes sacrificing gear to be a much more important choice, since you can negate some of the damage. I figure NPCs must always take the maxed out damage value, and players must always take the rolled portion of the crit. Just so that even if someone negates a player crit it's still a solid hit, and if a player negates a crit it's much more valuable.