Armor Penetration is Crap!
I was just using
against a
and he literally sat there and spammed the laugh emote while I used my full combo (W > Q > AA > R > AA), he only went to about 70% health, then ult'd and of course melted me because I'm a squishy.
Update: I read your comments, but I fully disagree with the whole "assassins should never fight tanks" since there are items/masteries/runes specifically made for you to penetrate defenses. No reason I shouldn't have been able to melt Malphite with that build. I know I'm supposed to focus the squishies but the squishies 
were dead! Which left
against
and since we all had AD champs except
and they had armor, they killed all 5 of us.
That is a major balancing issue. Could we have had better team comp... yes, but regardless, Camille, Graves and I were fed 5/0 or better and they were all negative, just stacking armor. How is that fair?
. I thought armor pen was specifically so I could melt tanks if I was ahead.