First in to kill off anyone using Cincinatti and chili in same breath.
Personally I don't like the fresh chopped veggies thrown on the top at the end.
I have become a fan of throwing in corn in the last 30 minutes. Yellow or yellow white color gives a different look on the eyes and the sweet taste can take some of the sting off the heat from peppers. More of a Sante Fe or Tex Mex style.
While I like to mess around and experiment I always load mine up with dark and light kidney beans, black beans, and some sort of white bean. I'll mess around with different meat cuts too and will use anything from beef, poulty, deer meat, etc.
usually get a bag of the red/yellow/orange sweet peppers, jalepenos, red pepper, chili peppers, poblanos and maybe fresno and aneheim. More a process of what looks good at the grocer than an exact recipe. I don't need to blow the roof off, you just want some warm heat that hangs on after each bite and for a good 20-30 minutes after you finish a bowl.
Fritos scoops or tostitos scoops, mexican crema (or sour cream) and any mild cheese shredded on top.
If you do it with plenty of beans and lean meats and avoid loading it with dairy products at the end you actually get a very healthy meal low in fat and with plenty of protein. Get low sodium canned veggies or get them fresh to control the sodium.