How about instead of a health bar, or regenerative health, there be an actual damage system?
I just recently finished STALKER: Call of Pripyat for the 3rd time when it hit me, why isn't the health system in STALKER ever thought about?
Hear me out, when a person takes damage on STALKER they take a little initial damage and then begin to bleed. More bullets increase the bleeding effect. The only way to stop the bleeding (effectively) is to apply a bandage. Even after using the bandage the blood loss/HP loss is still there, which could regenerate similar to Call of Duty if a compromise HAD to be met.
Theoretically this would do away with a lot of the problems being faced on FPS games to date. Games would stop becoming who can twitch shoot the best and would be more focused towards who can shoot without being shot (I think we can all agree THAT would take skill). This could also make sniping much more balanced as the bullet could still do high damage but the bleeding rate would be lower, meaning snipers would have to actually snipe...from a distance...like an actual sniper. Also, like STALKER, body armor reduces impact negation but once the bleeding starts there is trouble. I think the closest analogy would be in RPGs with the poison Damage Over Time systems, particularly found in (never going to believe this) Two Worlds. The DOT stacks with every hit so without attention the character is going to die. Maybe this would tone down on the rushing run and gun bile being spewed out across FPS games these days.
Oh, if this is ever used in a game, I'm not suing because this isn't originally my idea. (talking to James and all them from Extra Credits)