One of the things I things I would like to see added to LoL is a time penalty for leaving a game which is reflective of the time that the player would have been in a game for.
Recently I have had a few games where players, admittedly playing champs new to them, lost their lane pretty hard. They would go afk in the fountain and eventually the announcer would announce they have left the game. Problem is that when this happens around the 10 min mark the remainder of the team have to play on until 20 so as to surrender. Whereas the player that quit can wait out a 5min penalty for quitting a game and move on into a new match.
It would be good if the time penalty for quitting a game was reflective of the game which the player quit, with a minimum 5min. So if a player quit at 10min they would not be able to que for another game until their original (quitted) game had atleast reached the surrender point.
At the moment if someone is loosing hard in lane and doesn't want to play anymore, and its less than 15min in, they can just quit and start afresh whilst the others on the team are plodding along until 20min.