This game will NEVER be balanced.
inb4 season 2-3 guys come in wagging their canes
http://boards.na.leagueoflegends.com/en/c/memes/leKvTTNA-riot-trying-to-balance-their-game
that post describes this game perfectly
Other than Riot's now questionable balancing and champion design / rework team, this game is hardcore meta based. People follow the meta like it's a religion, they obey it and if someone breaks it, thou shall be reported for unskilled player and prayers from the meta worshipers would be sent to have you put into the fiery depths of Bronze 4.
It doesn't matter if Riot we're to somehow make this game 'fully balanced', people find what's the best and abuse the (insert naughty word here) out of it. Nerf AP and AD? Well Juggernauts and Vayne it is! Base health nerfed? Assassins! More magic resist items? F*** playing AP, all AD teams (and vice versa). Think out any scenario of a buff or nerf and just think what the meta followers would do and you'll find that there is NO super buff or nerf to bring this game to harmony or close to it.