Seriously, nerf tanks.
There is no reason that a champion who can 5v1 and survive for a good 15-20 seconds needs to do more damage than a carry at all levels. If you wanna be tanky, fine, be tanky. But you trade damage for being tanky. -- at least that's how it works in most games. Here at League, we think it's a great idea to make the most invincible champions one shot people. 'cause, you know, balance.
Games are decided by who has more tanks, these days.