"Ghost House SMB1" from Super Mario Maker on WiiU
Composer: Koji Kando
Game Developer: Nintendo
I first heard this theme on my first day with MarioMaker. It was playing in the background of a very cool custom level called "Bad Plumbing." It was ghost-themed, and I didn't know where the music came from, but I noticed it instantly. Because the original Super Mario Bros did not include ghost houses, a new theme had to be made to suit this new environment. I think it sounds great. Appropriately low-fi and spooky, but still sort of poppy and catchy in a Mario kind of way.