"A human in clanging plate armor holds her shield before her as she runs toward the massed goblins. An elf behind her, clad in studded leather armor, peppers the goblins with arrows loosed from his exquisite bow. The half-orc nearby shouts orders, helping the two combatants coordinate their assault to the best advantage.

A dwarf in chain mail interposes his shield between the ogre’s club and his companion, knocking the deadly blow aside. His companion, a half-elf in scale armor, swings two scimitars in a blinding whirl as she circles the ogre, looking for a blind spot in its defenses.

A gladiator fights for sport in an arena, a master with his trident and net, skilled at toppling foes and moving them around for the crowd’s delight—and his own tactical advantage. His opponent’s sword flares with blue light an instant before she sends lightning flashing forth to smite him.

All of these heroes are fighters, perhaps the most diverse class of characters in the worlds of Dungeons & Dragons. Questing knights, conquering overlords, royal champions, elite foot soldiers, hardened mercenaries, and bandit kings—as fighters, they all share an unparalleled mastery with weapons and armor, and a thorough knowledge of the skills of combat. And they are well acquainted with death, both meting it out and staring it defiantly in the face." - Player's Handbook

The most diverse yet possiblly one of the most easy classes in the game, the fighter. A usually melee class, the fighter has many different paths to go down with their fighting style. Being able to use most weapons, they can deal great amounts of damage, or help block or take damage for other party members. Even ranged isn't bared from them with bows, javelins, and other thrown weapons. Their many different subclasses can have completely different play styles as well. So it is fair to say that this is the class to play if you want to possibly do anything. Role-playing wise fighter's are also usually varied, but are usually rather direct with their intentions, but that can be different depending on the player. Overall this class, while containing an overwheleming amount of options, is actually very good for new players to D&D as once you chose what you want to do, fighters are fairly easy to play as.