seems like this two places in Tokyo...

http://gundamguy.blogspot.com/2010/09/walking-akihabara-yodobashi-camera...

and this

http://gundamguy.blogspot.com/2010/08/visit-to-asobit-city-akihabara.html

I always really enjoyed shopping at various Tokyu Hands department stores. They usually have a hobby/action figure section on the uppermost floor. This is where I'd usually find Transformers and other figures, sometimes at clearance prices. Kiddy Land is also worth seeing, IMO. And Medicom used to have a retail storefront of sorts in Shibuya which was also pretty neat.

There's a distinction between a "hobby shop" and a "toy shop", in my experience, which was quite a while ago, admittedly. I found I preferred toy shops in Japan, which offered more figures, whereas hobby shops offered mostly models.

Give Mandarake a try, they've got a dozen locations around Japan including one in Akihabara where I'm sure you'll end up. Best part about them is they buy and sell used, open box, and damaged box figures so you can get a good deal, often much lower than new or aftermarket prices. Plus they're English-friendly, I love browsing their online shop.

Emerje

as usual, you've helped me again, and didn't even mean to! What method of shipping do you choose when ordering? I'm buying.........wait for it.........the new Yamato( I couldn't pass that deal up!) but my wife aint real happy with me at the moment. Don't worry, I blamed you
Rod

Here's the Tokyo 101:

There are 2 kinds of toy shops in Japan. Department stores such as Yodobashi, Isetan, Takashimaya, and Hobby Shops. Department stores tend to carry a wide variety of things (think Walmart) with a small section on toys. Hobby shops are like Comic stores but the ones in Japan can be very specialised. There are hobby shops that SOLELY deal with Transformers, Gunpla, or Figures and nothing else.

- Department stores:
Skip most of them unless you want real kids toys like plush and baby chew toys. Look for 2 electronic stores: Yodobashi Camera and BIC Camera. Almost every big town in Tokyo has one or both. They usually have a whole floor dedicated to toys, split into sections: Kids, Gunpla, anime Figures, customising tools, and Video games. It gets overwhelming.

-Hobby shops
Mandarake, as Emerje says, is a 2nd hand store dealing with collectibles. Dont be mistaken. In japan, 2nd hand usually meants C10 MISB. In the unusual case where something has been opened, expect massive price cuts. The biggest is Nakano, just off the main Tokyo area, but WORTH a visit. It's like 2 floors of various 2nd hand shops, each focusing on different things. Robots, anime, (bleep), diecast cars, comics, anime cels...

Here's a list of all the Mandarake stores in Japan
http://www.mandarake.co.jp/en/shop/

The next big stop for toys is Akihabara, or Akiba. Mainly a town that's dedicated to electronics, maid cafes and toys. Things have moved around since the big quake, so I don't know how accurate info on the web is, but Danny Choo has lots of pics. The toy area is littered with dozens of small hobby stores both big and small, selling everything from gashapon to carded toys, to big expensive statues to hobby art supplies. Some stores also have 2nd hand items or have rent-a-boxes for other customers to sell their own stuff at their own prices. One place you'll want to visit is the new version of Radio Kaikan... I think it's now at the Radio Store:
http://www.e-akihabara.jp/en/map.htm

If you want revoltechs you MUST get to the Kaiyodo store there.

The best deals in Tokyo are gotten by digging around. Every store prices things differently and it's a Forrest Gump box of chocolates. You never know which store may be desperately clearing out that super expensive item for 1/5th of retail, and every store you visit may have that holy grail cheaper. Or not. So plan your budgets, and be happy with finding any kind of better deal.

Thanks guys, appreciate the advice. Let's see if the business trip comes together and I'll hit as many of those places as I can.

I would love to visit the following locations someday...

Evangelion Store Tokyo -01:
http://www.evastore.jp/real/index.html

See the 1:1 scale Gundam in Odiba, Gundam Front Tokyo:
http://gundamfront-tokyo.com/en/

Some day...