Dark Age Of Camelot
Believe it or not, the pseudo-historical, Arthurian-themed MMORPG Dark Age of Camelot (DAoC) launched back in 2001, but it was originally conceived as a graphical multi-user dungeon (MUD) before becoming a full-blown 3D title.
At the time, its main competitors were Microsoft's Asheron's Call and Sony Online Entertainment's EverQuest. While the game still has fantasy elements, DAoC never seemed quite as cliche, borrowing from the obvious lore and locations in Great Britain.
While the game was never as popular as EverQuest, DAoC comfortably seated itself into second place and has remained popular ever since. DAoC is also the first MMORPG to implement realm-versus-realm gameplay, allowing players and their allies--whether a faction or an actual realm--to fight against a common enemy. This means that players in the Albion realm can battle against players in Midgard or Hibernia, depending on the situation.
DAoC offers a 14-free trial for new player, while the monthly subscription rate is the typical $14.99.