Countries categorized by continents and type. Creating countries isn't that hard and you only need to fill out fields that have a red "Required", anything else is just optional. If you think that a country that someone else made - like me - doesn't have enough information you can ask the person in the comments if you can add something to it, so they can edit the entry. The most fleshed out countries are those that actually manage to fill out all fields (which is so hard that even I can't do it alone).
By the way, if you want to create a country there are a few more things I need to know that aren't in fields: the country color (you can even give me a hex), its shape and size and where it is positioned on the map of its continent.