Depends on the Community. Of course if there are to many Wizards you got a Problem.
Personally until 120 Cap just Wizard/Cleric or Rogue/Cleric or a Heuksal/Ice/Light Nuker.
At the 125 Cap (Of course with the new 122-124 Skills) Warriors/Cleric / Warlock/Cleric and Rogue/Cleric are hell.
Speaking of the new "Hell's Fury" (Dare Devil but 3 Hits) which doesn't split the Damage at all means you can deal up to 1 Million Damage with the first Hit and than around 400-600 Thousand Damage with the other Hits.
About Warlock they get a 50% Mag.Damage Increase / 40% Defense Decrease Skill. You deal almost like a Wizard, personally I tested it and I killed Demon Shaitan in just 5-6 Minutes while doing 70-90k Damage each hit (13-16k Damage with a DoT Skill)
Rogue Cleric gets a new "Dagger Desperate/Crossbow Extreme" Skill, it's now 80%. Well never tested them at that Cap but as i heard it, they do hit pretty hard but their Defense is meeh^^.
You won't kill an "High Level Unique" with an Warlock/Bard/Blader/Glaiver below the 125 Cap since they just lack powerful Skills