Software
NosTale
NosTale (The Tale of Nomads of Silver Spirit) is a totally free MMORPG that includes simple (but beautiful) graphics and also lots of class options.
AdventureQuest Worlds
AdventureQuest Worlds (or AQWorlds) is an easy but very popular browser-based massively multi-player online Role-Playing game.
Star Wars: The Old Republic
Star Wars: The Old Republic is an Action, Massively Multiplayer Online and Role-playing video game developed by BioWare and published by Electronic Arts.