the question should be what makes the best hamburger?
you can use beef trimmings that are between 70% lean to 80% for most and remember the flavor comes from the fat
your only other choice is ground chuck, which most people will makes the best hamburger and ground chuck will run 80% lean
so the meat is pretty much generic except one other variable would be how long you cook it ie rare medium or well done. I say just cook it to 165 degrees to avoid the e-coli problems
whoops, one other choice is angus beef
so all of these favorite places there must be more than the meat?