I would prefer crits to reside in the optional, super-crunchy tactics module. I would rather they were not in the core combat rules.
I'd like something close to my homebrew.
A critical hit deasl double damage. Then you get a confirmation roll to get a bonus based on class, race, weapon, theme, etc.
So a elf rogue who rolls a 20 on attack with his longsword deals maximum damage on his 1d8 damage roll. He then rolls a confirmation of the hit. If he hits again he may any one of the following effects.
Longsword: Double the base weapon damage
Rogue: Add sneak attack damage
Elf: The target is dazed
Sailor: The target is disarmed
In 4e to-hit was no.1 consideration for offense as it was. Go and do this, character design becomes "What is EVERYTHING I can do to up my to hit...and forget about upping damage as upping to hit does the exact same thing as well as improving my odds of success"
D&D has always maintained accuracy & damage as two sides of the offense coin. If you made accuracy contribute to damage in this way, you break that and make offensive capability all about to-hit...which is something I wanted them to back off from.
Im more for the difference between your to hit and targets defence contributing to lowering the target number for the crit e.g. if your target to hit is 8, drop the target to crit to 19, if your target to hit is 5, drop the target to crit to 18...or something along those lines

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.