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Every other week, we examine the most popular Facebook games (according to monthly active users), looking at the top titles and developers on the social network to see who's attracting or losing players.]
While key Zynga releases like
FarmVille and
CityVille remain as the most popular social games on Facebook, at least one recently launched title has climbed up the list and could even overtake
FrontierVille soon -- Playdom/Disney's "hidden object" game
Gardens of Time.
CityVille still has more than double the audience than any other title on Facebook, 89 million monthly players. It's followed by three more Zynga games:
FarmVille with 44 million users,
Texas HoldEm Poker with 35 million card players, and
FrontierVille with 14 million virtual pioneers.
Gadens of Time, which debuted on the social network two months ago, has grown rapidly to nearly 13 million users. The game has players using a time machine to "locate hidden objects throughout history, unravel the intrigues of a secret society, and protect the world from sinister forces."
The sixth most popular title on the site is Gaia Online's Pokemon-style RPG
Monster Galaxy, which launched last December and now has 12.5 million monthly players. At #7, Zynga's 20-month-old game
Cafe World is still entertaining some 12 million patrons.
Rounding out the top ten, we have PopCap's
Bejeweled Blitz with 10.5 million, trailed by Wooga's
Diamond Dash with 9 million (debuted in March), and Electronic Arts/Playfish's
Pet Society with 9 million. Zynga's
Mafia Wars just missed the cut with 8.7 million virtual mobsters.
You can see the full list of the top 20 Facebook games along with exact monthly active user counts below:

All charts and data are courtesy of Facebook application metrics and trends site
AppData.