Nico Nico Douga - Misaka Odoru by KIA

Also this mix is hands down the greatest rendition of Kokoro Odoru of all time.

These maps are so silly, but fuck they are fun to play.

This goes for a lot of old maps, but no one would unironically map like this today, which I find all the more impressive as mappers from this era were able to create unique maps that are beloved by a good number of people to this day. Not a lot of people, but a respectable chunk.