Junkudo Books - Ikebukuro Station East Exit
Junkudo is a very big bookstore (about 10 stories high) with everything from magazines to children's books to best sellers to the classics. There is a whole floor given over to English books only. One nice feature in this very nice store is that there a chairs dotted around the whole building on every floor, so you can just sit and read to your heart's content while you are deciding to buy it or not!
There is a cafe in the store but for those of you who prefer comfortable chairs 2nd story) and your favourite blend there is a Starbucks next to Junkudo. So they are located together on Meiji Dori (Meiji Street).