OK, here's one that I've used a few times and like really well. It's not my recipe, but I do add a teaspoon of ground cinnamon to it.

1/2 cup paprika
1/2 cup kosher salt
1/2 cup light brown sugar
1/2 cup granulated garlic
6 tablespoons granulated onion
1/4 cup chili powder
1 tablespoon fresh ground black pepper
1 teaspoon cumin
1/2 teaspoon cayenne pepper

I whipped this batch up about an hour ago. It's a 1/2 portion of the recipe above and is enough to generously coat about three slabs of ribs or two average size butts. Has a great flavor that isn't overpowering and isn't too spicy. Give this one a try, you'll really like it.

We've got relatives in from out of town and are having a family pot luck tonight. If I get all my chores done in enough time this morning I'll be using this rub on some St Louis cut spares around noon.

After a quick spin in the food processor