An epic game demands an epic grade.
Europa universalis 3 is, by far, the best Paradox title, and the most expanded too, reaching now 4 expansion packs and 2 game packs that facilitate its aquisition for new players: The Europa Universalis Complete, which contain the In Nomine and Napoelon's Ambition expansion packs, and now the Chronicles, wich adds the Heir to the Throne and Divine Wind expansion packs.
The game is a grand strategy at its best. You grab any existing country in the period of your chosing and lead them to glory (or doom, if you're not that good player) in a great time spam from 1399 A.D to 1821, from the end of the medieval europe to the death of Napoleon.
As any good empire-building game can be, Europa universalis 3 is very open ended. In one game you might see France becoming a giang empire, ruling not only a great part of europe, but of the world too. In other game, France might not even live past the medieval age and be swallowed by Burgundy or any other neighbor, and all of that in the hands of the AI. So the possibilities are vast.
Don't worry about micromanagement. The game uses a very simple economy based on products manufactured in the provinces and their value in the Centers of Trade your province trades through.
So, a center of trade composed by a lot of provinces with exotic products, is of great value, and to trade their you only have to send in the merchants. Success is not 100% garanteed, obviously. Your merchants will compete with others merchants of all the other countries and their success depends on various factors, like your technological level, reputation, prestige among other nations and so on...
The technology system is equaly easy. It's all based upon sliders and levels. You will divide your monthly budget among the technological areas, like Government, Trade, Production, Land Military, Naval Military and so on...
Each level in one of these areas will better your country's performance in that area. Levels of government will bring new forms to administrate your country, leaving the backwater Feudal Monarchy to a new administrative monarchy, or even switching to a Republic governemnt, for instance.
The trade techs level will enhance your merchants chance to be successful in the markets of the world, bringing more gold to you in return, etc, etc...
This is a highly recommendable game, mainly if you're into empire-building ones. Take a small country and transform it in a prosperous empire that will last through the ages, and be glad that there is such a masterpiece to take you for the ride.