Doing away with the melee lunge is the best way to handle the situation. The knife is for those times where you have nothing else to defend yourself with, not for just running into a room and clearing it by mashing the melee button.

1. Get rid of the knife entirelly.

No Need. Although the game would be no worse off without it, only better if the choice was knife as it is now, or no knife at all, make no mistake about that.

COD has allot of problems as it is, Lag compensation, interpolation etc however this knife has, added to the current problems, pushed people I know over the edge, they play BF3 now.

2. Get rid of the knife entirelly and return to using your gun to butt someone.

This would be fine so long as it is not the same one hit insta kill whenever you are even half close, as this removes any close quater gun fights, for the simple reason, it takes zero skill or effort to press a one button INSTA KILL.

EDIT on thinking more about this, this could be a fantastic idea, making a good solid GUN BUTT, but it must do 50% damage, meaning, 1 hit kill if enemy is <50% health, 2 if 51% or above, this is VITAL and actually I think, a GREAT idea!

3. Make the knife something you have to equip before you can slash it.

Certainly an idea, perhaps hold knife button for 1 second before it equips and slashes, or just equips, then this would remove what is most irritating about the knife, having somebody choose to one button insta kill you because it is FAR easier then trying to aim and shoot and control recoil with a weapon

4. Have guns do more damage at "melee knife ranges" so that if you need a single bullet or two to drop someone about to stab you.

Far better options are worth considering that this

5. Create a "Knife Vest" as a perk or similar that protects you.

Possibility, as if you wear one or not, (unless you make it clearly visable on the models) it would discourage people from one button insta killing you on the basis they would not know if it is worth trying to or not, I guess? shame some people would have to give up an entire perk just due to the ridiculous knife though, I still say better options are available

6. Changing the tuning of the knife to do variable, or half, the damage it does right now

A fair possibility

7. Do nothing. We already nerfed the melee lunge/attack range.

NO, NOOOOOOOOOOOO, the knife system is AWFUL, the most powerful weapon in a first person SHOOTER is the KNIFE, this is RIDICULOUS, the knife is not a LIGHT SABER, common, you should not be able to one button INSTA KILL anybody who is even half close to you, even if they are pumping bullets into your chest, this is INSANITY.

8. Do away with the melee lunge entirely.

There should be NO lunge, unless the animation is as follows, if you are to lunge at somebody and plummet your knife deep into there flesh enough for them to be insta DEAD, at least make a DEAL of it, if you do this, make it a penetrating stab which lunges you maybe even to the floor taking them down, making you vulnerable significantly, BF3 has the knife really well thought out, try knifing somebody who has a gun from the front lol but if you get behind them, you can grab them, and drag them into a position and slit there through, this is really well thought out, this ofc leaves you vulnerable, the knife should be only useful in certain situations if we are honest, want to take somebody out quietly from behind? that's a fine idea.

There are an ABUNDANCE of ways a knife system can be implemented, and many ways which could be successful, but it is first important, MOST OF ALL, to understand WHY the knife system as it is now, is very wrong, only then can a new way be thought out clearly.

Spamming this is against the forum code of conduct. and will not get any more votes.

"2. Get rid of the knife entirelly and return to using your gun to butt someone."

YES,YES,YES!!! That!!! This!! etc. etc. Go back to gun butts and have them do 50 damage. There are only a few things I want in life. Balanced secondaries, dedicated servers, good shotguns and number two on this list. Doing that would bring me so much closer to nirvana.(not the band)

Make it happen 3arc! You know what, balance out knives and your next game is a day one buy, even if all the critics give it a 0/10.

I think 2 or 7 .. i dont really know which . but here is my view.

First, I'd like to point out I loved running with knife only , but my thumb no longer works properly and just cant knife at all most of the time.. so take this as a non-biased opinion from someone who usually only winds up recieving.

But I think it is good to have an instant melee of some sort. maybe 3 - 4 feet in range.

It doesnt have to be lethal, but powerful enough to compete with a full auto rifle . Thats where I think the gunbutt is ok. something that would ring the guy's bell for a couple seconds like the effect of a  stun grenade. Then maybe a second hit to kill.

But certainly keeping the knife the way it is, but needing to equip it woud be useless. Likewise, a 2 hit kill would be useless unless it disoriented the enemy long enough to actually have a chance for a second melee. Making theguns do more damage at melee range isnt that great either. They drop you fast enough at that range.

Lastly ........... it's gotta have a cool animation. Personally, I like the swipe over the tac knife stab just for effect ... although the recieving end of both stink. All you see is a guy coming at you, and you die.. What was really awesome was the bayonnette from WaW. I think that was the coolest of any melees in the series.