I don’t have a specific favorite national anthem, but I will take this opportunity to recommend the Slovak Philharmonic Orchestra’s renditions of every national anthem (plus a few regional and historical ones), which was one of the main things that started my interest in national anthems. [Youtube] [Invidious]

A few countries have changed their national anthems since it’s release, but it’s mostly up to date.

Actually, the Democratic Republic of the Congo and the Republic of the Congo are two separate countries that border each other.

Edit: Just to add to the confusion, there used to be more Republic of the Congos.