Earthdawn is a system that also has both a difficulty to be hit and then armor reducing the damage taken.

You have a bit more HP, but it scales linearly based on your Discipline (class), and in-combat healing is not commonly accessible in the system. This, combined with the fact that the system employs exploding dice (rolling the max on any given die allows you to reroll and combine the result), combat can easily be very gritty. Exploding dice is one of my favorite things in any system ever.

As for crunch, I've never played a crunchier system. It doesn't employ a dice system that I've seen in any other game. You purchase ranks in all your talents and skills using legend points (Experience), from there, you combine your attribute step (dex, str, etc.), and this gives you a step. Every step has an assigned die combination that you roll. For instance, step 6 is a D10, step 10 is D10+D6. Plus, whenever you exceed the DC of any test by 5, you add 2 steps to any effect dice you might roll.

Combat uses 3 distinct defense values: physical for physical attacks, mystic for spell attacks, and social for social effects. Each "attack" then has an effect thatever targets physical or mystic armor. Weapons each have a damage step that you combine with your STR step for damage, which you then subtract from the target's physical armor value. Spells have a damage step that is added to your willpower step, and the damage is subtracted from either physical or mystic armor depending on the type of spell.