I have taken to making really mild chili, using dried peppers rather than spices out of a bottle. Then, if I want heat, I add it at the time I eat it, and I add a little to a sample before I dump it all over a whole bowl. This eliminates the "too hot" problem.
If you love hot stuff, you should explore some of the hot sauce sites. A decade ago, before my son left home for college, we used to buy a dozen bottles at a time and tried out all sorts of pepper sauce. I assume someone must have done a poll on this forum at some point, asking everyone for their favorite sauce. There are a lot of good ones. There are also some absolutely horrible ones, including some that are completely unfit for human consumption (like "Dave's Insanity Sauce").