I live in the U.S., and I use Collecting World Coins by Krause, because I speak English and own only circulating money. However, I would use a more comprehensive coin guide if I had more coins, such as the world coin guides by century published by Krause or Siegs guide for the Nordic countries. What do most people in Scandinavia use? I assume they mostly own the Siegs books.
We use both catalogs....But if you are in one of the Scandinavain countries the Siegs book is more likely to be used over the Krause book and the opposite if your in North America.