My preference is this build:
http://rift.zam.com/en/stc.html?t=0M...oos.Vcdm0qo.Vh
Gets you:
AoE damage finisher and combo-point group heal (awesome) and the healing/buff bonuses from bards.
AoE (Rain of Arrows) and pet tanking/DPS abilities from ranger.
Significant bonuses to damage output (especially bard abilities) from Nightblade.
Then I make one of the 5 this spec:
http://rift.zam.com/en/stc.html?t=0M...cbMVqs0V.Vhx0h
Gets you:
Bard healing + resonance + Anthem of Fervor. <-- AoF is critical IMO as with this build it reduces everyone's energy use by 13%.
Damage bonuses from Nightblade.
You can't get enough pet points at this level to get AoF & Rain of Arrows so there isn't any point in taking ranger, IMO.
With the above 4+1 setup, running 3 pigs and a wolf, I was invincible in major rifts and nearly invincible in elite zone invasion events. And raids for invasions will LOVE your constant group healing (I shift to using bard-only abilities in invasions).