3 ingredients make an amazing burger. 
1) Quality beef, 85-85% 
2) Quality sea salt, healthy dosing
3) Quality pepper at the end
-when I say quality, I mean a good quality, not a brand. lol...
Go to a local farmers market and purchase seasonings there. It's almost always better quality and just as much if not a little cheaper to purchase. 
Anyways...have your burger near room temp before going on and cook to med. The salt will create a nice crust and when mixed with the fat that will come out of the burger...it just makes the best burger ever. 
I have spent a ton of money on all of those rubs, shakers, etc and always came back to the salt and pepper burger. The thing I dont like about the rubs, shakers and seasonings...in the end, you taste those instead of the meat. I do think that rubs and such have their place, but not on a burger.