Grey Health
This is not a QQ thread. I am one of these TK players that people despise and I absolutely love playing him so Too Bad For You everybody.
Grey Health is one of the greatest things to grace this game. I think that the ratio of damage-to-tank as far as TK is concerned is way overhyped by the community, and I think that fitting the mechanics of a champion within the framework of stuff like Grey Health to open up their power in certain areas while leaving other components reigned in is an awesome way to make a new Champion. Same goes for Rumble's Heat, or Renekton's fury.
I really hope that Riot designs more champions that fit within these frameworks. They are super satisfying to play--I would sign a blood-ledger and forfeit my soul to the dev team for a tanky AD brawler that utilized grey health in a different way, or an off-the-wall full tank that utilized the same Heat resources as Rumble to reign in it's ability to otherwise smolder the enemy team.
Please Riot :^)