Pork Barbecue Spice Rub

I am interested in your thoughts about what makes a good barbecue rub. As hint, I have listed some basic ingredients that are prevalent in many commercial bbq rubs available today (in no particular order) and purposely left off the specific quantities of the particular ingredients.

black pepper
sugar
white pepper
oregano leaf
salt
paprika
chili powder
onion powder
garlic powder
cayenne pepper
chipotle pepper

If you've never tried to construct a barbecue rub from scratch, I urge you to try it and test it out on your own bbq the next time you're in the experimenting mood. Please respond back to this post or via e-mail re: what you think the quantities should be for your ideal tasting pork bbq rub.

I'll post the recipes to share with everyone.