Which class when played with skill affects your group the most?

[Brut]

Good puller isn't necessary at all if the group has good dps and/or CC. You don't need to split the pulls if the team can handle multiple mobs at a time, in which case you can have any class just run into the next room and aggro the next 3-4 mobs.

Necro is the same as ranger, does a bunch of roles mediocre, so if your group is otherwise bad I guess the necro gets to shine. I wouldn't say it affects the group the most, it just helps if the group is otherwise terrible.

A well played bard quickly elevates a group from average to awesome. It's the best.