One for all
When one for all came back in around 2014 or 2015 if I remember correctly, I was very disappointed that it wasn't in Howling abyss and that not everyone played the same champion. That lead to the point that especially around my skill level at that time, mostly everyone there played for win not for fun. The thing with Howling abyss one for all was that everyone had to play the same champ that was voted. That voting system imo worked perfectly as many would vote for just fun champs not only ones that would be op in the gamemode. Another thing with Howling abyss was that it immediately was a 5v5 where as in Summoner's rift it took quite long for everyone to group in mid and the early game was spent in lane farming.