#1 Hated ADC to fight.
I personally hate one ad carry out of them all, I think some of them are weak right now, but i also think a few are too strong. regardless, I want to make clear that IT'S NOT THE ITEMS THAT CAUSE CERTAIN CHAMPS to be near impossible to deal with outside of straight counter picking. Just in case riot gets in any ideas. [slayer-jinx-wink]
as for my vote it goes to:
vote away ^w^
add this defense ignoring monster to the list

Easily. I play support quite a bit and he is easily the only ADC you cannot counterpick or counterplay. You just have to hope he's stupid and gets hit by the poke.
,are 2 champs i'd recomend. Not on any statistics but because on can displace twitch and the other would be able to follow up and counter any movement of twitch early, mid, and late game.
because he takes no skill and just right clicks you for 200-200-200-1000 damage at level 5. Then when he gets his ult he 100-0s you with undodgable shots because you get f---ing slowed. He also has a stupidly long ranged snare for no reason at all.

tbh, with second place going to top lane 
and 
as a squishy is instant grey screen.

She can stunn and slow you and you can't do anything about that.
, but the drop in damage is noticeable from another item being focused, it makes it much easier to duel them later. early game is hell if your immobile.