Nakano is mostly famous because of Nakano Broadway (i.e. Otaku's heaven). There you can find a multitude of otaku goods, from vintage to rare. Nakano is also a nice place for students to hang out since there are nice parks and cafes and it has a laid-back atmosphere compared to some posh areas of Tokyo.
Coffee isn't only about getting your caffeine fix. When done right, good coffee is an art. Sometimes you want to stray away from the major coffee chains, and you want to add a little local flavor to your brew. If this is the case, this are places you need to visit in Shibuya for your cup of Joe.