Crystal Saga - Crystal Saga is an Action-Adventure, Free-to-play, MMO, RPG and Fantasy-based video game.
Realm of the Mad God - Realm of the Mad God is a best online hack and slash video game that includes pixel style graphics.
Wizard101 - Create your Wizard here and play for free! Wizard101 is an online Wizard school adventure game featuring collectible card magic, pets, and duels.
Runescape - RuneScape is 3D Action-Adventure, Massively Multiplayer Online, Role-playing, Fantasy-based and browser-based video game developed and published by Jagex.
LaTale - LaTale draws heavily from some other 2D side scrolling video games to provide a great fantasy MMORPG world.
AdventureQuest Worlds - AdventureQuest Worlds (or AQWorlds) is an easy but very popular browser-based massively multi-player online Role-Playing game.