Here's the 6th day!
Day 6 - Favourite parent-child relationships
Bobby Singer to the Winchesters, Sam & Dean. Like the picture says, 'Family doesn't end with blood'. Bobby's such a father to the boys. And the three of them work great together.
Day 7 - Favourite rivals
Day 8 - Favourite partners-in-crime
Day 9 - Favourite family unit (four or more people)
Day 10 - Least favourite pairing
Day 11 - An "OT3" or threesome
Day 12 - Favourite Person and Animal Companion Relationship
Day 13 - Your first pairing
Day 14 - Your most recent pairing
Day 15 - Favourite non-canon pairing
Day 16 - Pairing with the best chemistry
Day 17 - Favourite canon pairing
Day 18 - Favourite group of friends (four or more people)
Day 19 - Favorite band of villains
Day 20 - A pairing you like, but don't like what canon did/is doing with them
Day 21 - A pairing you think gets too little attention
Day 22 - A pairing that a lot of people ship, but you don’t
Day 23 - An unpopular pairing that you like
Day 24 - A pairing you think are actually together behind-the-scenes, but it's not confirmed in canon
Day 25 - A pairing that you have grown to like but didn't at first
Day 26 - Favourite childhood pairing
Day 27 - Pairing you think is the most adorable
Day 28 - A pairing people would be surprised you like
Day 29 - Your favourite of all the relationships you've posted so far
Day 30 - Free choice!