GURPS has hit points. Someone else will have to speak on behalf of HERO, as I'm not sure at this stage.
Hero has hit points- actually two types of hit points, representing Stun and Body damage. This represents the comic book and action genre pretty well, in that people often get hit and stunned or knocked out, but it's fairly rare to take a potentially lethal wound.
Let's see....
Star Wars/D6 had a damage condition track, where being stunned was a lot more common then being seriously hurt. So did James Bond.
Traveller had damage directly reduce one of your physical stats. Reducing one stat to 0 lead to unconciousness, two to serious injury, and three to death.
Traveller 2300 had a damage mechanic based on hit location and rolling against the damage factor of the weapon. You generally had a choice between doing a medium wound or a stun, or a critical wound/injury, or death/injury. Itwas fairly fast and lethal.
Albedo uses damage levels based on hit location, as well as blood loss represented by accumulated loss of fatigue.
Both Risus and PDQ have damage remove dice from your abilities, with IIIRC, the target choosing what ability to lose dice from. I believe in both you have to justify why getting hurt could damage your ability to cook, or your relationship with your girlfriend. It may sound weird, but it's actually a really fun mechanic.
Cyberpunk, Storyteller, Shadowrun, etc. all have limited hit points and condition modifiers. *yawn*
Dogs in the Vineyard has a unique damage system called Fallout, based on how far you want to take a given conflict. You could stop a conflict at speaking or fisticuffs, or go on to lethal, and the amount of Fallout is based on how much you're willing to risk to win orhow far you were willing to go when losing. Fallout can include a number of effects, ranging from being discredited, to injuries to death, and IIRC, fallout is also connected to gaining experience.
What's more: 'If D&D didn't have x (. . .)' claims have become increasingly amusing over the last 20+ years. . .
Meh, I find them similar to the "D&D needs a critical hit system" claims. Been there, done that, played Arduin.