Hi, new here from Colorado. I like Risk but haven't played for years. Used to be a fanatic when I was younger though. What are all the variants out there?

I love Risk. I have 4 different Risk editions and the Risk/Castle Risk combo. I also have Castle Risk all on its own as well as Risk 2210, Godstorm, the Clone Wars edition, the Star Wars Original Trilogy edition, the Lord of the Rings version, and the Transformers edition.
Back in college my friends and I played all the time. We set up a Risk tournament and even played a game that involved 25 of us playing on the same board. We each had a different color and style; the general colors of black, green, blue, red and yellow in stars, roman numerals, army miniatures and wood and pink stars, purple stars, brown roman numerals, pink wood, and grey army miniatures. It made for a very crowded game board. We started on a Saturday and played 14 straight hours with only 2 people being eliminated. The game took us 22 days to finish with us playing around classes and club activities. I won the game thanks to some early treaties and dealings. That and the sacrifice of my friend Matt's armies who acted as a barricade against the last three opponents while I built my armies up southeast Asia and Australia.
I have purchased a board from a version I already own and divided the territories further in the off chance that an opportunity to play a twenty five player game comes around again. The combatants will all have at least two territories now.
I think the other versions are fun, but none compare to the original, except Castle Risk on occasions.