Massive Online RPGs
Online stat-builder games with persistent characters, a character development system that requires endless hours of play to progress, endless quests and equipment hunts and interaction with lots of other players. Examples range from text MUDs to EverQuest, EverQuest2, World of Warcraft, Lineage 2 and various defunct games like Asheron's Call 2.

Once upon a weekend dreary, I chanced upon an MMO weak and weary... err me, not the MMO. How can that be so much clearer in Poe's original...