Zergling- Raptor evolution with Metabolic Boost. Ridiculously fast and can jump cliffs? Hope you were never planning on mining and leaving your base at the same time.
Baneling- Hunter Strain with Rupture. It launches at you to explode. And with 50% more explosion. Better GG now.
Roach- This one is tough. Almost certainly Adaptive Plating for super burrow regen, but I think I'm leaning more towards Vile Strain (assuming debilitate means they take on more damage) because...
Hydras- Frenzied Hydras attacking 50% faster with Roaches causing the units to take even more damage? That packs a bigger hit than a Carbot Immortal.
What are your choices?