If you want a high house rating then listen up! Here is a list of item that will get you 7,777 bonus pionts it also tells you where to get them from!!!

Arwing (StarFox): Spotlight item at Nook's.
Dracaena: Spotlight item at Nook's.
Ivory Piano: Spotlight item at Nook's.
Jack in the Box: Have Jack play three tricks on you on Halloween.
Lafty Lucky Cat: Buy from Redd.
Lovely Phone: Gift from Katie and Kaitli.
Lucky Black Cat: Buy from Redd.
Lucky Cat: Buy from Nook.
Lucky Gold Cat: Spotlight item at Nook's.
Master Sword (The Legend Of Zelda): Spotlight item at Nook's.
Music Box: Gift from Katie and Kaitli.
Piggy Bank: Put 100,000 Bells in bank.
Raccoon Figure: Buy from Redd.
Samurai Suit: Spotlight item at Nook's.
Treasure Chest: Spotlight item at Nook's.
Triforce (The Legend Of Zelda): Buy from Redd.
Washer/Dryer: Buy from Nook.

I hope this helps!!!