I dunno, OP said that Civ IV "looked boring". Civ IV is like brighly colored unicorn candy compared to EUIV or CKII.
I've played both. They are 2 very different kinds of strategy games.
Europa Universalis series and Crusader Kings are historically accurate games. In fact, if you are a gamer that knows very little about history, you'd be totally lost and clueless when "events" come up for your nation. Events are like multiple choice things, turning points which will steer the direction of your nation. Does England choose to become a Naval power, or a Land power? Historically, the correct choice was that England chose to be a Naval power. But the game gives you the choice to do the exact opposite. When an event called the "Treaty of Kasr-i-Sirin" comes up for the Persian Empire, do they choose to make peace with the powerful Ottoman Empire who could easily steamroll their Persian butts? Do they make partial concessions? Or do they spit in the face of the Ottoman ambassador and choose to ramp up their centuries-old war of Shia versus Sunni? The choice is yours when you are the Shah of the Persian Empire.
EU4 and CK events are in the hundreds. They are triggered scripted events. For example, the event that allows Kingdom of England to become the "United Kingdom of Great Britain" requires that England must have first conquered some parts of Ireland, and has subjugated all of Scotland. Without achieving those goals by a certain date, you have zero chance to ever become "Great Britain" (which boosts your economy, prestige, and awards you a boatload of victory points).
They are turning points that let you guide your empire towards historical outcomes
. or if you think you can do better than history, then you go against the historic choices.
Civilization 4/5 is a very attractive strategy game, but it only pretends to be a historical game. In fact, there is never any "historically" accurate map when you start as a Civ. Most of the time, you start on a randomly generated terrain map. There is only token history in the Civ games, like for example the German Empire has strong "militaristic" advantages. Yes German Empire was historically a military nation. But that's a very general stereotype. Eye candy and graphics is fantastic in the Civ games. Historical accuracy is minimal.
