Back in the day, I loved Rolemaster's criticals -- except that they sometimes meant you spent more time designing your character than playing him, before he died spectacularly.
In fact, one of the flaws of most critical systems is that they ignore hit points, when hit points are how the game system models avoiding getting killed.
Warhammer got around this in a clever way. In Warhammer, you don't roll on the critical-hit table when you roll high to-hit; you roll on the critical-hit table when you've dropped someone. The table tells you
how you finished someone off, not
that you finished them off. That's easy enough to import into D&D.
Melhaic said:
I like combat grim and brutal, so I use the system from 2E Combat & Tactics. With the 3E ranges. Yeah, I like dismemberment.
Any "threat" is a crit: none of this cockamamey confirmation roll BS. Damage and effect are based on weapon size relative to the critee (a hobbit critted by a greataxe is ogre jelly). The critee makes a fort save equal to damage dealt, and if it fails he/she/it/they suffer a specific injury.
The crit ranges and multiples were specifically chosen for balance, and the roll to confirm a crit plays in important role: it means that better fighters score more crits than lesser fighters (like orcs).
If you want more crits, I suggest going in the opposite direction: increase all crit ranges to 1-20 (any roll), but still roll again to confirm.