In the current meta of LotV i face these roach-ravager pushes, nydus-allins and so on. I guess many have problems with this kind of openings. Therefore i looked for some build order which is good in defense as well as in the offense.
And thats what i got:
Hellbats and Ghost supported by Medivacs
The first Hellions should be used to harass the Zerg to deny the ramp up of drones while already on three bases.
Ghost can join the battle with Medivacs on large maps later on.
Around 5:00 you can decide whether to attack with 8-10 Hellbats + 2-3 Ghosts + 1-2 Medivac(s) or defend any aggression if scouted.
Advantage: Hellbats tank Roaches and Speedlings, Ghosts can snipe Roaches and Queens.
Attention when Zerg is going early Mutas!
While you push:
Add 3rd CC, more factories/starports and go for Hellbat, Tank, Liberator
Surviving Ghosts can be used later for nukes or Vipers (EMP or snipe).
Transition is very important, you may want to scan the enemy base before attack to build already hard counters.