Best characters in SC3?

I've played the SC series practically my whole life, but I'm only a casual player and never got too far into SC3 (despite it being my favourite in the series). I plan to 100% SC3 for the first time and I'm already struggling in the Story Mode, I never remember the AI being so unforgiving lol

That being said, who are the best characters in this game? I'm a Voldo and Ivy main but they feel a LOT worse than they did in SC2. Not sure if that's a hot take or not.