24. Cabal Online
Cabal Online is another entry in a long line of free-to-play action MMORPGs from Korea, and although it's one of the older ones, its stronger points have allowed it to maintain relevance despite the appearance of a host of competitors. The combat itself is fun, and it employs a fairly unique combo system that delivers more damage if you time your attacks correctly. It's more complex than it probably sounds, and getting the most out of Cabal takes hours of practice.
What's more exciting, however, is using those combos in duels with other players. Not only can you unlock special titles (and sometimes, special skills) by becoming one of the game's best duelists, but you can also bet on the outcome of those duels. It also benefits from a complex honor system that rewards or punishes you for engaging in straight PvP, and a decent helping of content updates keep its devoted community coming back for more.