In desperate need of voice chat
Some would argue that nothing in league of legends is worse than ganking for a lane, pinging your arrival ahead of time and then watching as your laner fails to realize you are there and you get killed by the enemy laner. For me however I think it is much worse to be the one that goes "oops" when I don't realize something is happening because I'm too distracted killing minions or getting killed while typing. Anyways I think voice chat would go a long way to stopping a lot of these scenarios and with league being so team based it would be awesome.
UPVOTE FOR VOICE CHAT!! YEAH! :)