On butts, we make our own rub adopted from Cheryl and Bill Jamison's book Smoke and Spice. It's called Southern Succor Rub and seems to have just the right amount of heat. They have another one called Wild Willy's Number One-derful Rub that I put on my ribs and chicken.

Southern Succor:
1/2 Cup of Ground Black Pepper
1/2 cup of paprika
1/2 cup of turbinado sugar
1/4 cup of kosher salt
4 teaspoons of dry mustard
2 teaspoons of cayenne