The map below says it all, but just in case here's a link to the article. It's a little old being 2015 but is still interesting. I read elsewhere that overall the most popular candy in the US in 2019 was M&M's followed by Reeses Peanut Butter Cups followed by Snickers bars.
https://www.influenster.com/article/americas-favorite-halloween-candy-state-by-state
https://www.influenster.com/article/americas-favorite-halloween-candy-state-by-state