Feel free to vote one, some or all or suggest others. Only requirement is game having trading goods as major component of gameplay and otherwise would fit GOG's catalog (so no MMO's and mainly multiplayer games).

/ [url=http://www.gog.com/wishlist/games/1869_video_game]1869 (video game) - Mobygames

Anno 1404 Gold Edition / Dawn of Discovery - Wikipedia
Anno 2070 - Wikipedia
Anno 2205 - Wikipedia

1193 Anno Domini: Merchants and Crusader - Mobygames

Civilization IV: Colonization - Official site - [url=https://en.wikipedia.org/wiki/Civilization_IV:_Colonization]Wikipedia[/url]

Commander: Conquest of the Americas - Official site

East India Company Collection - Official site

- [url=http://www.mobygames.com/game/gloriana]Mobygames

High Seas Trader - Mobygames

Merchant Colony - Mobygames

Merchant Prince / Machiavelli: The Prince - Wikipedia
Merchant Prince II - Wikipedia

Ocean Trader / Der Reeder - Mobygames

Patrician IV Gold Edition - Official site

Pirate Hunter - Mobygames

Port Royale 3 - [url=https://en.wikipedia.org/wiki/Port_Royale_3:_Pirates_%26_Merchants]Wikipedia[/url]
Port Royale 3 Gold

Ports of Call - Mobygames
Ports of Call Deluxe - Mobygames

Rise of Venice - Official site
Rise of Venice - Beyond the Sea
Rise of Venice Gold

Sid Meier's Pirates! (2004) - Official site - Wikipedia

Sub Culture - Mobygames

The Guild 3 - Official facebook page - Forums

Uncharted Waters - Mobygames
Uncharted Waters 2: New Horizons - Mobygames
Uncharted Waters III - Wikipedia

Pick your own poison:
Merchant / Trade-oriented and Space trading and combat oriented game lists at Mobygame

PS. I intentionally left out space trading games for now at least. I may go thru and add them later if and when I have the time.