Just a very simple idea, but if the devs limited chameleon to 85% like your armour then the massive abuses you could exploit in Oblivion would be impossible in Skyrim. Anyone agree or have any more really simple easily programmable fixes/tweaks to make Skyrim a better experience?

Simple fix is to make a very high chameleon very very very hard to get. And by very high I mean 85-90%.
Also constant effect chameleon from armors shouldn't add up on each other.

This is my opinion.
But I don't really care much about chameleon anyway. But that's because I've never really used it

Disagree, if someone wants to do that then they should be able to.

They should make it so that NPCs and critters that have a Detect Life spell/potion/hability to be able to use that to detect you, if they see or feel something wrong (a 6 feet claymore disapearing into thin air or someones head rolling on the floor, for instance).

making it impossible, no.
making it tough to get, yes.

this is actually one of the best weapons of a thief/assassin character. they just need to work the AI around so that when they see someone get killed by an invisible person, they don't just stand there looking at the body, but they freak out instead

This is my opinion, but I also think chameleon should just make you unseen. Not unheard.
People should still be able to hear you. That way even 100% chameleon is not god mode.

On a note, I think this should also go for invisibility. In no one could hear you even if you were just invisible.
Invisible/100% chamelon only equals being unseen according to me

It's a single-player game. If someone wishes to use exploits it affects no-one but themselves. This reminds me of fast-travel debates. Why should a game be hard-coded (?) to suit those with no self-control?

I don't understand what the deal with this is. It's a single-player game, people should be free to do whatever they want. If it was an MMO, for example, I'd understand...but, honestly, why do you care? If people want to cheat let them cheat, what's it to you?

I've never used chameleon myself, but if people want to do it, why not? Why is it that big a deal?

If this is such a problem get rid of chameleon and keep invisibility.

I'm with the "give NPCs countermeasures" people. Let people be 100% invisible via chameleon, but give the enemies a chance to find them. If they have magic available, they'll use things such as detect life. If not, they could hit blindly around them if they hear footsteps close or shoot in the general direction of where they suspect the player to be, if the player is using ranged attacks. Perhaps some well guarded places could actually have passive counter-magic (special variants of dispel) or, more profane, paint on the floor, or something else in which footsteps are easily seen. Same applies for snow outside.

I think giving them good countermeasures like Spec said should be enough. If you are good, you could down one person and move and then the other people would look for you where the attack came from, giving you another attack.

If you had enemies which hunted their pray via means other than sight (like in the film Tremors where the monsters were attracted to noise). Than this would not be an issue

The mechanics and differentiation between chameleon and invisibilty could be improved greatly and there is some good suggestions here. A lot depends on the capability of the new AI.

This.