Nakano for vintage/used. Some great cards and outside the market there is a ton of nightlife and great restaurants. Keep in mind that it does not feel as crisp and clean as Akihabara, but that’s part of its charm. You won’t go wrong either way. Nin-Nin, Magi Pokemon, and Manadrqke are great

Near Akihabara if you want to be a geek, Toshima city for the Pokemon Mega Store and Ghibli Store, and Shinjuku for nightlife. But anywhere close to a train station and you can get nearly anywhere easy.