
This is a megathread for
Realm of the Mad God because the other one is too old.
RotMG is a top down sprite RPG with 18 different classes.
The five basic classes are Wizard, Priest, Archer, Rogue, and Warrior:

The Wizard is the default class of Realm of the Mad God and has an AOE special attack, wears Robes for armor, uses Rings, and has a staff with 2 bolts shot at once for his stats.

The archer has a long-range attack and can acquire very powerful weapons. His Ability is his quiver, which fires a very powerful, piercing, single arrow.

The rogue relies on his speed to deal damage at medium range while avoiding attacks. His Ability is a Cloak which allows him to go undetected by enemies for a time.

The priest attacks at long range and can heal himself and his allies.

The warrior deals the most damage of any class and can wear strong armor to protect himself from enemies. His Ability grants extra strength and speed to those around him for a short time.
And some more advanced classes:

The paladin is unlocked by reaching level 20 with Priest and Knight. Can deal damage at close range, wear armor and heal himself and his allies.

The knight is unlocked by reaching level 20 with Warrior. Deals large amounts of damage at close range and has the highest potential defense of any character. His Ability provides extra defense in addition to damaging and stunning enemies.

The assasin is unlocked by reaching level 20 with Rogue and Wizard. Fights from medium range and uses poison to damage his enemies over time.

The necromancer is unlocked by reaching level 20 with Wizard and Priest. Drains life from his enemies to heal himself and his allies.

The huntress is unlocked by reaching level 20 with Rogue and Archer. Uses arrows and traps to defeat her enemies.
Realm of the Mad God is a game with randomly generated worlds, and occasionally once about 25000 monsters have been killed, all players are summoned to Oryx'x lair (The mad god) to fight him.
This is a bit like LoZ, now go play it.