What is counterplay vs Garen?

Kiting CC Peel Armor/Magic Penetration Percent Health Damage Armor

But if you are not an adc, think of it this way:

Garen is an AD Caster who excels at dealing with other melee range casters. If you are highly dependent on your abilities, and you have to get into close/melee range to deal your damage, then Garen typically is very effective against you. This is why he is the natural Riven counter. Riven is a close range AD caster who is crazy reliant on her abilities to maximize her damage output.

So, the easiest way to counter Garen in lane is to pick someone who has ranged poke/kiting ability (Gnar and Teemo are your most usual choices).

If you have to pick somebody melee range I suggest that you choose someone who is more reliant on autoattacks for damage, rather than abilities.

Teamfight wise it's pretty much what Endless says. Just lock him down with CC/peel and make sure he can't dive the damage dealers. Anything that would do to stop a Riven at that point is probably enough to stop Garen.

max % health true damage.

Don't kill somebody. Duh, what are you a noob?

lee sin

maybe

If you're the villain just don't engage ever, even if he's 1/11.

Heimerdinger with a Liandrys and a Rylias. That and kiting.

All valid points, but don't your responses fall into the category of counterpicks? It seems that Riot constantly bandies about the idea of counterplay being a thing, but in my experience it seems that more and more champions have less holes in their armor unless you luck out and can troll pick against them...