You'll be hard pressed to find a better (let alone any other) game set during histories most exiting period. So your duty and plant the Queen's Colours in faraway lands, bringing glory to yourself and your country and civilization to the dark continent! Where Crusader Kings II can be called an assassination simulator, and Europa Universalis IV a map painting sim, Victoria II could very well be labelled as an economic game at heart, with conquest simply serving to supply your nation with what it needs to conquer more land for more resources for more land to gain more resources to...you get the picture. That is not to say it is stale in any way, far from it! Victoria II will give you hours upon hours of enjoyment. Heartily Recommended.
I will add that to get the most out of this game, both "A House Divided" and "Heart of Darkness" are absolutely necessary, they not only fix a great deal of issues with the game but make colonizing a much more immersive and challenging task and sure to bring all the more glory to your Queen and Country!