Weird idea here, so bear with me.
Right now, champs that auto attack are kind of... cancerous, right? ADCs are assassins, assassins chunk half your health in one auto thanks to Duskblade, and champs like Yi and Jax and the like are just not fun to play against. They all have the same issue, in that they're based around auto attacks, which, outside of Graves and Kalista, have no counterplay. They always do the same damage, they attack so fast that armor means nothing, they sustain like gods, and they're more or less statchecks.
So, what if we made a change to give them meaningful counterplay without destroying the reliability of autos?
**In short: Let's give long range autos different zones of effectiveness, and let's give melee autos positional requirements.
In this picture you can see Ashe's full auto range divided into smaller circles.
* The inner circle does 50% damage. Why? Well, think about it: If someone with a fucking sword or something is charging you from like 5 feet away, you're not goinna have a lot of time to aim, or a lot of room to move around in. So you would be less effective, yeah?
* The outer circle represents the dropping velocity of the shot -- even bullets have drop off. So it does slightly less damage.
* Between the inner and outer circle, you have the "sweet spot" where you get full damage from your autos.
So, what does that accomplish?
* It makes ADCs play slightly closer to the fight, which means they're more in danger during teamfighting.
* It increases the skill disparity between a good ADC and a mediocre one.
* It gives ADCs a weak point that can be exploited (their zone that does less damage)
* It makes positioning more important.
As for crit, what if crit chance increased the size of the "sweet spot" while crit damage increased the damage of that zone? That way, even crit has counterplay.
Then, for melee autos, here's another picture.
So, if you ever played FFXIV, you'll probably recognize this shape. It shows where the front, side and back of the unit are. What if we made melee autos rely on your position as well?
* The red area shows the front of the character. An auto there would do 75% damage -- in real life, attacks from the front are blockable, right? You see it coming, and you can dodge or block, etc.
* The yellow area shows the side of the character. Autos here would do 90% damage. It's harder to block attacks from your side, right? But you can still see them coming and get out of the way.
* The back, with no line (I drew an arrow so you can see what I'm talking about), is your weak point. You can't see behind you, and someone could wind up for a big hit. So autos here would do 100% damage, with lethality increasing that by X% for so much Lethality (maybe 2 lethality per extra damage %).
So, this gives even melee autos some counterplay, and would make top lane fights really interesting.
Now, I doubt Riot would do any of that, since it would increase the skill floor, and you lose money for having a higher skill floor -- but it'd make the game more fun, since everyone would be trying to out position one another and auto-based champs would really have to think about how to go in, rather than just run up and statcheck you to death.
I can dream though, right?
**TL;DR: Look at the pictures. They show auto damage zones. First picture is for ranged autos, second is for melee autos.**