Many popular Akihabara stores have an option to shop online as welt, where you can get all things Akihabara is associated with, such as figures, hobby items, PC, cosplay, anime DVD and games, without making a trip to Tokyo.
It is also a good way to check out a store before actually going there.
Anime DVD・games
Trader
Trader carries games, DVDs and blue rays.
Official site:
BOOK OFF
BOOK OFF mainly carries second-hand books, DVDs and games.
Official site:
http://www.bookoffonline.co.jp/
Hobby
KOTOBUKIYA
KOTOBUKIYA mainly carries anime, games and character goods.
Official site:
https://shop.kotobukiya.co.jp/shop/default.aspx
azone
azone carries goods related to Doll・Doll.
Official site:
https://www.azone-int.co.jp/azonet/
Volks Hobby Heaven
Volks Hobby Heaven mainly carries figures and dolls.
Official site:
Rashinban
Rashinban carries anime, games and fun-made products.
Official site:
Cosplay
ACOS
ACOS carries cosplays, wigs, shoes, and cosmetics.
Official site:
PC・PC related goods, smartphones, tablets
Sofmap
Sofmap is the most famous PC shop in Akihabara. It carries cameras and audio equipment.
Official site:
TSUKUMO
TSUKUMO carries homebuilt computers and peripherals.
Official site:
Janpara
Janpara mainly carries second-hand PCs, smartphones and tablets.
Official site:
arc
ark carries PC・PC and PC related goods. It also sells BTO which makes it a good choice for those who want to customize their computers.
Official site:
Electronics Retails
Yodobashi Camera
Yodobashi Camera is the largest electronics retailer in Japan. Its store in Akihabara can be seen in most Tokyo guide books.
Official site:
Onoden
Onoden is an electronics shop build 60 years ago.
Official site: