Fun fun fun!!!
I'm a pretty hardcore crafter, so when I learned that there was such a place as Tokyu Hands, I put it at the top of my "to do in Tokyo" list!
The Ginza store (there are several locations) is a smallish TH, only four floors... but there is a LOT packed into those four floors! There are materials and tools for a wide variety of crafts, hobbies and DIY projects. There are a lot of unusual materials to be had, so if you are a crafter, looking for something interesting drop by and poke around. I so wished I could bring home some tubes of lacquer, but it is not legal to ship via air freight. :(
The store also has a nice assortment of stationery and phone gadgets, luggage, books and a full culinary section where they hold demos from time to time.
If you make it out to Shibuya there is an even larger Tokyu Hands with a woodworking supply, full fabric section, and housewares. Such fun from such basic shopping. This is my kind of store!