The first is: If you think Tabasco sauce is "You're Trying to KILL ME!!!!" hot, then we can end this thread right now.
Tabasco, and many of its like in the Grocery Store out on the highway, come in about the same heat as a Jalapeno pepper. That is, at about 2,500 Scoville units.
The first hotsauce that came to my mind has VERY good flavor and a hotness to where THREE DROPS will add "Noticeable heat" to a GALLON of chili. The lowest rating I've seen for it is about 80,000 Scoville units, some batches peak over 100,000 because it is a small batch and natural ingredient product.
It's a shame that they quit making "You Can't Handle This Hot Sauce". NOW, I've got to find another favorite.
Fortunately, I know the source of all things Hot Sauce: