Game Mode Idea: Player Item Balancing
Players always think they know what is best for the game, right? After all we play the game so much, obviously we know better than actual paid employees (Mostly Sarcasm).
So why don't we give the players a chance to prove it? Riot would search for posts with balance ideas, or maybe do a survey. Take some of the ideas, maybe hold a vote. Take the winners and attach them to the items in a RGM. Let the players experience how other players would balance the items in the game.
Hell, if something turned out well, maybe it gets placed into Regular modes.