Yeah, no kidding. The way that works best is let the tank pull the mobs while everyone stays close by, then let the tank attack first to build initial aggro, followed by the DPS guys, while healer covers tank and only healing when necessary so as not to pull the mobs away. SO many groups I've been in just can't freaking keep it coordinated, so boom, people get wiped. Or you have one DPS dimwit that, like you said, wants to steal the show and look like the tough guy. I did plenty of dungeons in WoW and this was usually how we handled it and it worked pretty well, save for those few crazy exceptions, but generally, it was a solid gameplan.

Trust me, when I played DPS, I did NOT want to attack first. I figured let the tank (who was usually my brother) keep the aggro while I did the backstab rounds and all that other fun stuff. And yes, being able to use voice chat works wonders.