My turn to do some contributions!!!
-Minzy attends church and is in the same group as the girls who do. That's probably why they're close. Minzy thanked Sooyoung, Tiffany, YoonA, and Hyoyeon in 2NE1's album.
-In the case where people really wanna know what religion the girls are really in, which I think is not important, here you go:
-Sooyoung, Tiffany, YoonA, Hyoyeon, Jessica and Sunny are all Christians and part of 문미엔 (Moonmien). (Google if you dunno what it stands for.)
-Taeyeon has not really revealed her religion but she might have been exposed to Catholic or Christianity as you can hear her singing hymns during SNSD horror factory, the ep where Yuri faked possessed. She sang it around the part where they first entered the building.
-Seohyun is highly suspected to be Christian due to her well-mannered behavior but no one knows yet. The only sign is that she prays with both hands together but then again it might not mean anything.
- As for Yuri, little has been revealed about her.
-Hyoyeon has a belly piercing!!!
-Taeyeon parent's owned a Optical Shop.
-Sooyoung's sister Soojin got casted after appearing on Introducing A Star's Friend as they found her to be able to sing and fairly pretty.
-Sooyoung mother's didn't celebrate her first birthday because she was upset that she was a girl...
-Both Sooyoung and Sunny's parents wanted guys.
-Tiffany and Jessica was borne in the same hospital.
-Sooyoung and Jessica were bestfriends since trainee days and Jessica's pet name for Sooyoung was actually "Summer".
-YoonA actually eats the most in SNSD but Sooyoung eats in the most frequency.
-Sunny loves the camera the most, to the extend that even when she's in the background, she still tries to get the camera's attention.
-Hyoyeon and Miss A's Min were friends even before debut.
-Hyoyeon feels awkward when the group comes out to greet the media.
-Jessica and Taeyeon share the same vocal coach, who happens to be 2AM's Jo Kwon's too.
-YoonA debuted as an actress before as SNSD.
-Sooyoung sang the Korean Version of BoA's "Everlasting" for the Korean's broadcast of the anime "Inuyasha".
-Sooyoung and Yuri had a song together for Working Mum OST named "Kkok" which was well received and commended for their vocals but then afterwards, their lines in SNSD's songs got shorter.
-Seohyun's stage outfits were the least during her debut. (Mini skirt, spaghetti-strap or sports top or singlet; whatever you wanna call it, which ends at the top of her belly.)
- Seohyun had short hair once during SNSD and Wondergirls' collab stage but because everyone found it hard to digest, she never had short hair again.
-Taecyeon from 2PM is closer friends with Tiffany & Jessica rather than YoonA whom he had a rumor with, because they all came from America and that they spoke English.
-Jessica speaks to her mom in English although her mother is Korean.
-Sunny calls herself by her name when she's on the phone with her mom.
-Sunny has a Nintendo DS even before they endorsed it.
-Taeyeon initially thought that YoonA stuck rice cakes under her eyes when she first saw her.
-Sooyoung calls the girls kids instead of Unnie even tho she's the third youngest in the group.
-Seohyun only tasted alcohol after she became of age and that she's having it regularly for health purposes.
-Yuri has blended "Ma" which is chinese yam for breakfast drink.
-Yuri carries packets of chinese tonic drinks with her and Tiffany hates the smell of them!
-Due to Tiffany's initial poor command of Korean, she said her slogan for her name as Brighter than mushrooms instead of Gems.
-Jessica's scream is comparable to a dolphin's and she turns violent when she's afraid.
-Sooyoung's fanbase largly based on ahjusshi's!!!
(I am not an ahjusshi but she's my bias...)
That's all for now, largely cause I'm tired but if I received enough thanks, I might be provoked to post more!