Good G-Shock recourses on the internet:
Higuchi-inc, Japan: This is a tip of Chris Moy in NY. Katsu San is Oita based. He bought several watches from them. They have a very fast and friendly service. Shipping takes only 3 days from Japan to New York. They can also order watches that are not on the site. You will find the contact form halfway the English homepage.
Seiya, japan: This is another tip from Chris Moy. Seiya is a Tokyo based internet shop specialized in Japanese watches, including G-Shock's. Former TV-Commercial producer Mr Seiya Kobayashi san provides an excellent and fast service. He writes very good English, so he can be a useful resource of finding special editions. There is a contact form on his website.
HB Watches, Brooklyn, USA: This shop also sponsored the WatchUSeek G-Shock forum. Their service is great and they ship fast. They ship worldwide (well, that's an important issue for me living in the small Netherlands). The often carry limited editions.
Ozzie Japan, Japan: Elliot (a.k.a. Ozzie) is a bit different from all other sellers. He is a Australian G-Shock Collector in Japan, who is selling all of his G-Shock's, because he has too many of them and he's planning to go back to Australia. He once sent me pictures of his collection, it's huge! Don't look here to find a cheap basic G-Shock, he only has very rare models (and they have their price). It's also a nice place to view all those models, we hardly see for sale outside Japan.
Boris Affordable Watches, Hong Kong, Nice guy from Hong Kong. He sells different brands. He's a Seiko WIS, but also has a nice G-Shock's for sale!
Tiktox (U.K): Formerly known as JK Supplies. This shop sells the G-Shock conversion kit, when you buy a Double Velcro Watchband. Personally I have no experience with this shop yet, but I have heard many positive reactions from people who bought there.
Superchrono: I have not yet ordered a G-Shock there, but I have heard many good stories about this store that I had to take it up in this section. I hope to try there out their service fast.
G-Stock: Adan from Spain sells spare parts of Vintage G-Shock's and some G-Shock's. Check out regular his great sales. I have found there nice G's for great prices.
Javy's International ltd: Javy's shop is located in Hong Kong. He is the Authorized dealer of Casio in Hong Kong. He has a lot of limited editions in stock, and if he doesn't have it on stock, he can try to get it for you.
A Moment in Time: An U.S. based internet shop, selling selling a lot of current U.S. G-Shock models. Also an authorized dealer dealer of Citizen and other brands. Sells international.
Das Uhrenparadies, Germany: A nice store with the newer G-Shock and Baby-G models for a good price. The shop is owned by Katja Hildmann. The site is in German, but she speaks and writes English (see her contribution in my Guestbook).
Megatime, Germany: This site is in German. I have bought my "Heavenly High" at this shop. The site is in the German Language, and they have a good service. They shipped my watch to the Netherlands, so I think they will at least ship within Europe, and maybe worldwide.
Watch my Watches, Germany: Very friendly Bavarian internet watch shop, specialized in G-Shock and Swatch. He speaks English, but also Dutch! Has also a hotel, so if you're planning to collect your G-Shock yourself, you can add a vacation on it.