It’s a Windows Live Messenger week yet again, with the messaging utility coming in as the top non-game title on our AppData list of fastest-growing Facebook apps for the second week in a row.

Before getting started on the list below, note that Facebook has updated its formula for calculating active app users to remove those users who only interacted with an app through a like or stream comment. Some apps may appear to lose large numbers of users from the change, although mainly in the mobile category.

Here’s the top 20:

	Name	DAU	Gain	Gain,%
1.	City of Wonder	824,870	+438,684	+114%
2.	Windows Live Messenger	4,440,375	+291,977	+7%
3.	FarmVille	17,611,581	+274,271	+2%
4.	Frases Diarias	531,177	+241,089	+83%
5.	Entrevista tus Amigos	1,806,748	+201,108	+13%
6.	Millionaire City	1,294,695	+169,201	+15%
7.	Nightclub City	1,255,333	+144,507	+13%
8.	Car Town	793,697	+103,130	+15%
9.	Pet Society	2,490,160	+86,598	+4%
10.	HTC Sense	2,315,963	+71,590	+3%
11.	Kingdoms of Camelot	773,238	+69,188	+10%
12.	Ninja Saga	882,690	+68,624	+8%
13.	開心 Lounge Bar	319,743	+68,225	+27%
14.	Bubble Island	847,314	+67,868	+9%
15.	Mall World	879,190	+63,192	+8%
16.	The Hotlist	76,935	+62,691	+440%
17.	BandPage by RootMusic	151,482	+49,102	+48%
18.	Samsung Mobile	555,998	+46,834	+9%
19.	Backyard Monsters	224,983	+45,888	+26%
20.	@Smiles	773,927	+44,063	+6%

Ranking over even Messenger is City of Wonder, the newest Playdom game. This is the closest thing that Facebook has gotten to the time-honored Civilization series so far, so if you’re a fan, give it a try. We cover the other games, as always, over at Inside Social Games.

As for Windows Live Messenger, we’ve discussed the reasons for this app’s growth before. In brief, it’s a study in close integration of an existing, successful product with Facebook; it’s unlikely that Windows is gaining many new users here, but existing devotees of Messenger are certainly interacting with Facebook through the app quite a bit.

The remaining non-game apps are mostly long-time growers that have been coming up for months. Notably, the top two — Frases Diarias and Entrevista tus Amigos — are both Spanish-language, respectively a phrase-of-the-day app and a friend quiz.

As it happens, both appear to be losing monthly active users, while DAU is climbing somewhat. This may mean that these two apps are affected by Facebook’s tweaking of its formula, as mentioned above. HTC Sense, a mobile app, was definitely affected in its MAU stats, although its DAU has risen throughout the changes.

Dropping down to number 16, The Hotlist is an app we haven’t seen come up before. Based on a website, the Hotlist crawls your social networks to find events and places that your friends intend to be, and even gives a male to female ratio for its locations. Keep an eye out for our closer look at the Hotlist later.