It's the game that started it all for me. While it took a few months after getting my NES to finally own it (I had the misfortune of buying just as the pack in game changed from SMB to Urban Chamion), it was the game that first got me interested in video games! The mushroom power up, the hidden extra lives, the music that was so inviting yet could change tempo and stimulate tension! I'm so glad the franchise became so successful And like Mario, I'm still playing video games.
I also can't not mention how Creating my own Mario levels in Super Mario Maker is a dream come true, and is fitting 30 years on since Shigetu Miyamoto first created the first Super Mario Bros!