I hate playing against Jax
if i play mid/jgl i always ban malzahar, because it's noob champ, he get's free banshee (his passive) and ult is point and click, no need any skill.
-F
Jax or Irelia, any high-scaling melee champs that can still carry the game without getting fed.
Fiora,sion,hecarim and any kind of jungler xD
zoe, one shots across the map and a 1000 year old loli
I also hate playing against vayne
Pyke is toxic since he pub stomps low elo players. Definitely hate playing against a good top laner like Riven or Tahm