1.) Holding hands in the haunted house
2.) Making sweaters for the owls
3.) Pen-pals from Beauxbatons and Durmstrang
4.) Dressing up as muggle characters (like Disney) for the Halloween feast
5.) Always being invited to the ghosts' death day parties (because Hufflepuffs are always polite enough to talk to the ghosts)
6.) Ordering muggle candy (candy corns, chocolate bars, m&m) and sharing them with the whole House
7.) Enchanting the common room to smell like cinnamon
8.) Apple picking in the forbidden forest (with Professor Sprout)
9.) Competing to find the smallest pumpkin instead of the biggest
10.) Helping the house elves finish making dinner early... in return, the elves let them use the kitchen to bake pies