In our latest look at the Facebook applications with the most new daily active users (DAU) in the past week, we see an odd trend — at least according to what our AppData service tells us. Many of the apps that made the list appear to have done so through big spikes starting around Thanksgiving, last Thursday. From last Wednesday back through the previous week, we’d seen lower overall gains on the list.

It may be that people were so busy getting ready for Thanksgiving the week before that they didn’t have as much time to log on and play games. Then, with the Thanksgiving holiday weekend, they once again had the time.

	Name	DAU	Gain	Gain, %
1.	Happy Pets	1,906,178	+548,281	+28.76
2.	FishVille	6,806,371	+503,798	+7.40
3.	FamilyLink.com (formerly We’re Related)	1,137,900	+480,146	+42.20
4.	Birthday Cards	1,225,606	+393,058	+32.07
5.	Facebook for iPhone	8,975,807	+374,522	+4.17
6.	Petites questions entre amis	575,041	+358,650	+62.37
7.	Hug Me	500,528	+243,830	+48.71
8.	Zoo World	545,615	+199,654	+36.59
9.	Yearbook	277,923	+187,201	+67.36
10.	Christmas Cheer	337,098	+176,465	+52.35
11.	Birthday Calendar	340,464	+139,454	+40.96
12.	Diva Life	205,801	+137,603	+66.86
13.	Fish World	2,370,899	+131,593	+5.55
14.	FarmVille	26,589,135	+130,673	+0.49
15.	Fish Isle	478,146	+125,065	+26.16
16.	Paf le Chien	181,308	+116,055	+64.01
17.	Sorority Life	1,166,854	+112,663	+9.66
18.	Band of Heroes	158,975	+111,597	+70.20
19.	Facebook® for BlackBerry® smartphones	6,468,181	+107,695	+1.66
20.	Nicest Person Contest	194,375	+101,326	+52.13

At the top we have Happy Pets, the latest game by up-and-coming developer CrowdStar: The pet-caring app gained 548,000 new daily users this past week for a total of 1.91 million DAU and 5.77 monthly active users. This places it slightly above Zynga’s big new hit, FishVille, at least in terms of weekly DAU growth.  That app grew by 504,000 DAU, to reach 6.81 million DAU — a big number, to be sure. But as the app has grown to 21.8 million MAU within a few week of launching, it’s inevitable that not all new users who showed up as DAU in their first week of trying the game will still come back daily. Two weeks ago, it had 4.77 million new weekly DAU, and last week it had 1.15 new weekly DAU. This week is likely the longer-term DAU rate, as we discussed earlier today on Inside Social Games.

Moving down the list, family tree service FamilyLink.com (formerly We’re Related) and RockYou’s gift-giving app Birthday Cards both saw a slight rise in the last several days, after weeks of gradual decline. In terms of gift-giving and poking apps, holiday-themed Christmas Cheer. So did RockYou’s Hug Me.

Then we have Facebook for iPhone, the first of the three big mobile apps that consistently show up on all of our AppData charts. It gained 375,000 new DAU in the past week to reach 8.98 million DAU. The other mobile app that shows up here is Facebook® for BlackBerry® smartphones. At number 19 on today’s list, it grew by 108,000 DAU to total 6.47 million DAU. Almost on the list, at number 21, is Facebook’s generic Mobile web site, which shows up with 98,000 new DAU in the past week to total 5.03 million DAU.

Most of the list is games, as usual, and a notable one is RockYou third app on today’s list: it’s new game, Zoo World, which has been climbing up our charts since it launched last month. It grew by nearly 200,000 DAU last week to reach 546,000 DAU.

Also notable is the near lack of quiz apps on the top 20 DAU list this week, something we’ve seen in past weeks. A French one called Petites questions entre amis has more than doubled, growing by 359,000 DAU to reach 575,000. The only other quiz-style app is Nicest Person Contest, which grew more than half of its 194,000 DAU in the past week.