First off, don't buy the store made patties. Make them yourself.
I like to use 80% lean as if you go any leaner then that they can get a bit dry.
The biggest thing that I have discovered with making hambugers is not to compress the meat when you make the patties. Just lightly form them into the shape that you want. I actually will start with a package of ground beef and cut it with a knife to divide, I then lightly form them. This makes cooking them a little faster as they are not so dense and the less you handle them the more tender they are.
Put some fresh ground salt and pepper on them just before you throw them on the grill and let them go.... don't ever press down on them and flip them as little as possible.
Give it a shot.... you will be amazed at how diffrent the taste will be if you do it this way...
I add about 1/4 lb of minced chorizo to every pound of ground beef, along with ground fresh garlic and diced (as small as you can get them) vidalia onions. The chorizo will add lots of flavor due to the high fat content.
I put some of the bourbon molassas rub mixed in mine. It makes them really good. The camp stew is good too, but thats a different thread. If you do order, get the stainless peeler too.
I start the grill and throw on some thick cut onion slices and let them cook for a while
throw on the burgers and cook
just at completion put some good quality blue cheese slices on the top of the burger and cover the burger and blue cheese with a big slab of the grilled onion
cook for a while with the lid down to start the cheese melting
slap on a bun and dig in