I start with this one, and add as much of the red pepper as I want{which isn't much, it's alot in there and it gets really hot} I add the meat, and the tomato sauce that it calls for and then beans and sliced onions. It has most of the spices that are needed for chili and it has a wonderful taste, at least, I think it does. It comes with pre measured ingredients.
I use the same basic recipe most of the time, although I have one with beans and one without. Generally I'll just scale the heat for whoever is going to be eating it. For more zip, I usually go with more jalapeno peppers, garlic & cayenne.
Here's a link to mine. You can add as much spice as you like to heat it up. There are a TON of recipes on here for really earthshakingly hot stuff too.
Thanks everyone. I picked up the mix Texasgirl mentioned...added some peppers, onions, chopped up steak, chopped up chicken, ground beef, tomato sauce, kidney beans & crushed red pepper.
Then just to add to the heat I tossed in some Dave's Insanity Sauce. Served it up with some oyster crackers and needed a towl to wipe the sweat from my head while I was eating it!