Diablo 3 - Prepare for the last stand in Sanctuary
The Barbarian class is oriented towards surviving for extended amounts of time in the fray, trading attacks with numerous opponents at the same time. This is strongly supported by many skills within his ability kit such as War Cry. This skill increases the current amount of fury that the Barbarian has, while also raising his armor and the armor of his allies for a duration. If the enemies are trying to run away, one can always make use of the Seismic Slam skill, which deals damage from range, while also knocking his foes back. A barbarian can survive even the toughest situations, thanks to skills like Wrath of the Berserker - a short duration ability, increasing his Critical Hit and Dodge chances and Attack and Movement speed.
The Wizard class is a spellcaster, based around the use of various magical abilities. As such, Wizards rarely let any monster come near them, by using spells like Blizzard, to rain down gigantic ice shards upon their enemies, dealing heavy cold damage and slowing them in the process. And then, when the enemies are crippled by the attack, a Wizard can make use of abilities like Arcane Torrent and Meteor to rain down even more devastating damage on his foes.
Witch Doctors are mystical magical shamans that come from the deep, vast jungles of Teganze. They are adept at utilizing powerful dark magic, curses and supportive abilities that can easily turn the tides of a battle. By using Firebomb, a Witch Doctor can throw an explosive skull that deals heavy damage to multiple targets nearby. And when there is need to support his allies, a Witch Doctor can make use of abilities such as Mass Confusion and Big Bad Voodoo, forcing all nearby enemies to fight on his side and increasing every friendly target's attack, move and cast speed.
Monks are a class adept at quickly dealing high amounts of damage and supporting their team mates. The combination of these two things makes Monks incredibly valuable as party members. For example a Monk is capable to quickly dispose of multiple opponents nearby, via the use of the Way of the Hundred Fists ability, then shield himself and his allies from all melee attacks by deploying the Inner Sanctuary ability. In addition, skills such as Resonance, which increases the duration of his supportive auras improve his valuable team-oriented abilities even further.
Demon Hunters are professional monster slayers, combining devastating traps and abilities with deadly ranged attacks. In the Demon Hunter's arsenal there can be found numerous skills that make for a very interesting playstyle, such as Granades, Shadow Power and Back to Basics. First, a Demon Hunter can throw some Grenades that detonate shortly after being thrown, to lessen the enemy's numbers. Then, when the enemies are damaged and weakened, the Demon Hunter can make full use of the Shadow Power ability which increases her attack speed for a short amount of time. This can be further supplemented with the passive ability Back to Basics, which increases all the basic damage that is done by a Demon Hunter's weapon.