Habenaro and Datil pepper sauces #1 and #2. #2 only because it's so scarce; online order only and usually out of stock.
Scoville rating be damned, it's the flavor that makes them #1 and 2. Datil pepper sauce has a flavor unlike any other. Habenaro is a bit similar in flavor. Both garner similar Scoville rating range. I prefer those at the lower end of their range 100k-300,000 SHU
If heat were the objective it would definitely be Ghost peppers; in so far as Publix available. Made a large crock pot of sausages, cabbage, onions and carrots. Laid 3 Ghost peppers on top, covered and simmered. Removed peppers and stirred contents then replaced peppers on top. Covered and continued to simmer another hour. Removed peppers and served up a bowl full.
It was so freaking hot it was impossible to taste anything. Ruined the entire pot full. Can't speak to their flavor, don't know if they have a flavor. Those Ghost pepper surely gave Pepper X a run for it's top seat on Scoville Heat Unit rating.
Nitrogen. I'm of the impression that higher nitrogen soil content lends itself to a tamers pepper?