This week’s AppData list of fastest-gaining Facebook apps, measured by growth in monthly active users, doesn’t include a lot of non-game apps — but those that are present offer a nice cross-section of successful concepts.

Here’s the top 20:

	Name	MAU	Gain	Gain,%
1.	Pirates Ahoy	6,724,676	+3,063,492	+84%
2.	SocialBuzz	11,073,345	+2,560,740	+30%
3.	City of Wonder	2,606,883	+2,547,354	+4,279%
4.	Market Street	9,094,156	+1,182,008	+15%
5.	Are YOU Interested?	7,020,824	+969,538	+16%
6.	Car Town	3,664,060	+867,785	+31%
7.	Nightclub City	7,612,635	+746,208	+11%
8.	Millionaire City	5,860,862	+712,461	+14%
9.	Zapapa games	4,200,138	+640,771	+18%
10.	Tattoo City	2,256,775	+623,751	+38%
11.	Video Chat vChatter	1,960,136	+615,335	+46%
12.	My BFFs	8,728,308	+566,654	+7%
13.	Armies	2,392,900	+445,828	+23%
14.	開心 Lounge Bar	1,381,762	+431,956	+45%
15.	TripAdvisor – Cities I’ve Visited™	8,533,811	+417,256	+5%
16.	Monster World	2,934,658	+379,009	+15%
17.	Lucky Train	770,695	+351,260	+84%
18.	Games	6,272,726	+310,519	+5%
19.	Friend Block	2,451,928	+305,081	+14%
20.	snsplus	956,841	+300,487	+46%

SocialBuzz is once again at the top of the list, with 2.5 million players. Although it looks like a cookie-cutter friend quiz, in which users answer questions about friends and are asked to post the results to the friends’ wall, the interface is unusually polished.

Playdom looks great, with its two newest games, City of Wonder and Market Street, coming in together at the top of the list. One is the latest city builder, the other a retail game. The specifics of genre may be less important than suddenly having a Disney budget for advertising — although we did find City of Wonder to be a genuinely good game. We’ll cover the rest of the games on the list over at Inside Social Games.

Next up is Are YOU Interested?, a dating app that uses the time-honored Hot or Not formula, which loads up one picture at a time for users to pass judgment on. In this case, the judgment is “Yes” (you’re interested) or “Skip”, which moves on. AYI seems to have been growing much faster since it removed an option to say “Yes” without notifying the user whose picture has been loaded.

Video Chat vChatter, several places down, is a video chat app that has been growing well for a couple of weeks, while My BFFs, immediately following, allows users to create an alternate friend list indicating their best friends. Finally, TripAdvisor – Cities I’ve Visited is quite old, as apps go, but has just hit an all-time high point of 8.5 million MAU.