4x Warlock and 1x______

[zenga]

Priest gives you the option to run shadow / 4x lock; which is a very mobile team. You can do both pve/pvp content with them (lock pets are decent tanks up till cap level, where they fall short).

Paladin brings party wide crusader aura + buffs. You have a tank or a healer.

Depends what you are aiming for: pvp i'd say priest, pve i'd say pally.

[creyo]

i personally like having a pally in the mix for the tank option and they make really good healers as well but priest does have good synergy bieng able to go shadow with the warlocks for pvp.