Green animation for heals
When we deal damage, the enemy's health bar get a red animation showing the amount of damage he received. But when we heal, there is no animation. It would be really more enjoyable for healers to see with a similar green animation how much they healed.
This is always funny when you burst your enemy and you see his health becoming a big monochromatic red bar. For people who play healer champions, this would be as much funny if they could feel the power of their heals.