Vampire's Health Levels system was pretty elegant, simple and realistic.
For those not knowing it, everybody has 7 possible "injury" levels, each with an associated penalty:
So everybody had the same health levels, but a character with higher STA could soak up part of the damage. Let's say a sword swing does 5 damage, a regular human (STA 2) would take on average 4 damage, a top STA human would take 2-3. This solves the most common issues associated with hps: no inflation, wounded characters are penalised, etc.
Now that was a very realistic system and in theory is great, isn't it. But how well would it translate to a cRPG? For most rpgs, poorly. Vampires can heal easily and quickly, even in mif-fight, which makes the system good for a vampire game. And it was not a combat-centered RPG, at all. If you try to use this for a dungeon crawler, chances are it will kill the fun. Nobody likes to run around with huge penalties, so in the end what you do is force everyone to constantly heal between fights, and prepare yourself to use a lot of bandages/healing spells/potions with all the clicking and inventory management that implies. Plus forget about progression, imagine in the endgame you have attacks that do 2x damage compared to the beginning. It becomes too lethal to be fun.
WFRP 1st edition was a very good compromise. It is a HP system, (called them "Wounds", not HP) but it was non-inflationist within a system in which damage indeed scaled up. Average human has 7hp, and the most resilient hero ever has 16hp. Each blow typically deducts 1D6 or a bit more, depending on stats, armor, weapons, etc. 0hp didn't mean you die, but it meant a chance to become incapacitated plus any further damage would incur in scary critical hits, and half of them were lethal. Add to this that every natural 6 rolled had a big chance of being a crit and keep rolling and adding, repeating in case of another 6.
WFRP health system had other problems (naked dwarf syndrome) but it is probably my favorite system for a combat centered RPG. Damage feels scary, yet you can deal with a few wounds and keep going. More importantly, it still allows your character progression to allow you to gain "+1 Wound" and make you feel it makes a big difference. At the end of the day, we're all little mice in our Skinner boxes and if after a full game session we don't see our little numbers going up, even by a little, we feel sad, don't we?