I'd love to see an all-out 'damage mitigated' total. That is: heals + shields + health buff residue (ie: the effect Lulu's ult has on your health once its over, plus the damage it shields while active) + dodging and invulnerability. I don't think there's much point keeping the separate 'healed' stat -- the difference isn't significant enough to merit distinction within the overview.
It makes me a little sad every time I see my Lulu doing zero healing. Though S3 has made that less common (Mikael's Crucible most games, and Heal Spell sometimes), I'd love to know how much damage I'm actually mitigating.
I'd also like to see endgame stats which attribute the effects of various ally buffs to the buff giver, rather than the wearer. This would make the impact of many champions (most notably Sona), more clear. I suspect this would be incredibly annoying to track, as it runs counter to the way the buffs are implemented.