A recap of the current most active Facebook games over the period October 21 - November 19: FarmVille, Café World, Happy Aquarium, Mafia Wars.

The list of most popular Facebook games of the last four weeks is a telling report on who the big hitters in Facebook games development are. Once a developer is well known for a popular game, they strive to keep momentum going by adding extra features to the original game and attempting to replicate that success with other games suitable for the Facebook platform.

Game developer Zynga continue to rule the roost, owning six of the top 10 games:  FarmVille occupies the no.1 spot with a staggering 65 million monthly active users, while Café World, Mafia Wars, YoVille, Texas HoldEm Poker, and Roller Coaster Kingdom are all part of the Zynga family.

Playfish, a recent acquisition of video games publisher and developer Electronic Arts, has Pet Society and Restaurant City in their portfolio, while SlashKey is behind Farm Town, and CrowdStar made the no.3 spot with Happy Aquarium, a game that was one of the driving forces of the current hot trend of aquarium-themed games.

Zynga's new aquarium game, FishVille, lurks just outside the top 10 with 12,386,666 monthly active users accumulated since November 6.

The Facebook games with the most active users from the past four weeks on November 20 at 12:00 GMT are:

1.   FarmVille (65,658,188)
2.   Café World (28,798,718)
3.   Happy Aquarium (27,574,724)
4.   Mafia Wars (26,856,522)
5.   Pet Society (21,770,968)
6.   YoVille (19,485,289)
7.   Texas HoldEm Poker (19,375,735)
8.   Farm Town (18,336,745)
9.   Restaurant City (17,742,810)
10. Roller Coaster Kingdom (15,408,444)

Numbers in brackets relate to the total monthly active users.
source: appdata.com