I never write down what i add and it changes depending on what i have on hand, or what chile peppers look good at the grocery store, but I can name a few ingredients and techniques that have been a game changer for my chili.
#1 as crazy as it sounds, i dont brown my ground beef in a pot. I mix 1 TBSP of Goya Adobo AP w/pepper and 1 TBSP of chili powder to 2lbs ground beef. I take a baking sheet and a rolling pin and make a huge patty about 1/2 inch thick and bake for 15-20 min at 350F. After its done i remove it from the baking sheet and pat the excess grease off with a paper towel. After it cools i roughtly tear it apart with my hands to make nice size chunks. The benefit of this is you dont lose all that flavor of the seasoning as every bite has flavor, and also i prefer nice chunks of ground beef in my chili.
#2 I use chile puree as my base ( walmart sells it ) Its so much better then powder ( and very concentrated so use sparingly ) Its also less time consuming then making your own puree from dried chiles.
#3 Use Masa Harina ( corn flour ) to thicken. Benefit is it adds a subtle corn flavor and doesn't turn your chili white like AP flour, and its easyer to work with then cornstarch. I use more beef stock then needed bercause i like a more gravy like consistency to my chili.
Anyway, those are 3 game changers i figure i would pass on.