When people ask about my heritage, I just tell them "most of Northern Europe," because it takes too much time to list the 10 or so countries that I have ancestry in.
It's even hard to prioritize them. Does an Irish name mean more than a Swedish appearance? Does a relatively recent emigration from Latvia/Russia matter more than four ancestors on the Mayflower?
All I do know is that I have a lot of data on where my ancestors came from, which I have been plotting on a map.
I plan to use this data to design a map (or a series) that helps visualize where I'm from. It will either show the journeys my ancestors took to come to this country, or the cities that were very important to them.
Some screenshots of the maps I've been using to keep track of where ancestors lived: