I'd probably go with 5x Druid.

It is not my optimal team for PvE play, but it is pretty decent. You have the option of tank, healer, melee dps and caster dps, which is decent.

For PvP, you can go 5x Cat or 5x Boomkin, or mix healers into it. You can even run 5x Resto, which could be interesting in AV and Wintergrasp.

At the moment, Druids are my favorite class. And I've recently finished leveling the team to 80th. I love instant flight form, and the ability to collect ground spawn items without landing or aggroing mobs which are standing 1 foot away.