Mine is… damage based I guess. But what might work for me might not work for others, so this is just a suggestion.
On the front: Inquisitor, Assassin (middle).
At the back: Warden, Conjuror (middle)
Assassin for damage, and he’s pretty flexible. My assassin’s got 3 pieces of equipment that gives him +50 health steal, so he basically doesn’t need healing. I just put all the points in dexterity.
Inquisitor as tank and a just-in-case heal if the warden doesn’t get through. He also packs quite a damage, and I love using retribution, and because I put even points in strength and endurance, his retribution skill also does quite a lot of damage.
Warden as support. He’s got a passive buff that can remove one enemy buff upon hit, so that’s really useful for removing let’s say a +150% armor protection, or a ‘Demands enemy attention’ buff. He does sacrifice damage, but he makes a pretty good support/heal type. Even points in dexterity and endurance (for more survivability). If you get a Mosswood Crossbow (purple) for him, his heal adds even more hp.
Conjuror as DPS. I use this guy because he can summon additional mobs to do more damage. I find the war golem and shadow skill pretty useful. Plus, he never runs out of mana. All you have to do is use Power Siphon at the right time. The Electrocute skill also never misses, so it’s great to get rid of those pesky catgirl wannabes.
Hope this helps.