Custom Game Mode
I do like that Riot still likes to find ways to keep the game fresh, but let's be honest. The few of us that know it, every single game type that they have come out with has been previously invented by players themselves. Just before Riot released "All for One" there was a custom game client add on that allowed players to host and bug a custom match to make players all pick the same champ.
Way back before Dominion even existed, there was a client add on that allowed players to play on Twisted Treeline with six players on each side. It was a crazily fun game mode that only appeared for a few weeks, and all of you DOTA players remember the game mode with zero cooldown timers, and some crazy shenanigans. Riot implemented this into their own game and made it something absolutely awesome.
Let's look at a different game that had a wild success due to its ludicrous custom game modes. Back when Bungie released Halo 2, people played zombies on a few of the maps, with many many many house rules, and they picked up on it, and made it a legitimate game mode with Halo 3, and created forge mode for the players to make maps and game types with them.
I'm not saying Riot should make a Forge game type, but even by releasing the ability to change starting gold, income, base traits, and allowed characters, lots of game modes can be created. I would love to see Hide and Seek become a realistic game mode to be played on a regular basis by players, and I want to see what we all can make of custom game modes. The custom game community will flock to a player's idea, and take advantage of something fun.
Simple things can make a huge impact on the community.
