How Team Builder SHOULD be.
This is a very, very simple concept. This would make finding teammates easier, and it would allow for discussion beforehand. The idea is this: Allow players to pick only their role or lane when queing up, and then choose the champions AFTER being put in a lobby. This way, if someone wants to play a specific champion but can be persuaded to choose another for the role, it can happen. More importantly though, if a team has a full lobby of people who have their roles in mind, they can choose champions with synergy instead of simply declining ones they find that don't.
I don't know about you guys, but it's a little frustrating when I get into a lobby and want to play Yasuo, but of course no one else on the team has a knockup, and even if they're good with a champ that does, they can't switch. Or when a team has no survivability, or no CC, or all of one damage type.