Personal opinion, I like Physic+ more due to it's range, making it far flexible with positioning.
But out of Recover+ or Rehabilitate+, I would go with Recover+ due to it being more useful for most situations. When you consider that a lot of champion HP don't reach 50, that makes it that Recover+ is hitting usually around 66% (at worst) of the max health. If the unit has below 40 HP, then Recover+ is basically healing back to max. Meanwhile, Rehab+ would require them to be a extreme low amounts before matching Recover+ strength.