roadhog still ruins this game for me
He is seriously so easy to counter though.
Are you playing a character with decent dps at mid-range? Just attack him from outside of his hook's radius. Bait him into using his hook, and then get in closer for the kill.
If you're playing reaper, you don't even need to bait him. Just jump down on him from above and weave between his front/back so that he can't hook you, and it should only take 4-5 shots before he's dead.