I make my own, in two versions. The one I use for ribs and brisket has sweet paprika, garlic powder, granulated onion, dark brown sugar, coarse ground pepper, ground coriander (that I grind myself from the seeds), ground cumin and kosher salt.
The one I use for chicken, pork and fish is similar to the above, except I ommit the paprika and brown sugar and add lemon pepper, oregano and rosemary.
Cover meat liberally and let is marinade as long as possible. When you take it out of the zip lock bag, coat it with a little oil, then on it goes on a super hot grill to sear the flavor.