I really like the Cincinnati style chili (I’m a transplanted Ohio boy). I wouldn’t say it’s the best because there are many good chilis, but that style is VERY good and I miss it. On occasion we do our own 3-4-5 way chili. I should order some from Skyline or Empress.
Key ingredients are the cumin and the cinnamon and you have to get the balance right. If one or the other overpowers then the chili is ruined.
One other ingredient I always add because I think it puts a nice edge on the chili is a cup or two of very strong coffee. It adds depth to the chili and helps calm down the tang and acidity from the tomato sauce/paste.